RESUMO
The oral microbiota develops within the first 2 years of childhood and becomes distinct from the parents by 4 years-of-age. The oral microbiota plays an important role in the overall health/symbiosis of the individual. Deviations from the state of symbiosis leads to dysbiosis and an increased risk of pathogenicity. Deviations can occur not only from daily life activities but also from orthodontic interventions. Orthodontic appliances are formed from a variety of biomaterials. Once inserted, they serve as a breeding ground for microbial attachment, not only from new surface areas and crevices but also from material physicochemical interactions different than in the symbiotic state. Individuals undergoing orthodontic treatment show, compared with untreated people, qualitative and quantitative differences in activity within the oral microbiota, induced by increased retention of supra- and subgingival microbial plaque throughout the treatment period. These changes are at the root of the main undesirable effects, such as gingivitis, white spot lesions (WSL), and more severe caries lesions. Notably, the oral microbiota profile in the first weeks of orthodontic intervention might be a valuable indicator to predict and identify higher-risk individuals with respect to periodontal health and caries risk within an otherwise healthy population. Antimicrobial coatings have been used to dissuade microbes from adhering to the biomaterial; however, they disrupt the host microbiota, and several bacterial strains have become resistant. Smart biomaterials that can reduce the antimicrobial load preventing microbial adhesion to orthodontic appliances have shown promising results, but their complexity has kept many solutions from reaching the clinic. 3D printing technology provides opportunities for complex chemical syntheses to be performed uniformly, reducing the cost of producing smart biomaterials giving hope that they may reach the clinic in the near future. The purpose of this review is to emphasize the importance of the oral microbiota during orthodontic therapy and to use innovative technologies to better maintain its healthy balance during surgical procedures.
RESUMO
Hybrid-nanozymes are promising in various applications, but comprehensive comparison of hybrid-nanozymes composed of single-atoms or nanoparticles on the same support has never been made. Here, manganese-oxide nanosheets were loaded with Pt-single-atoms or differently-sized nanoparticles and their oxidase- and-peroxidase activities compared. High-resolution Transmission-Electron-Microscopy and corresponding Fast Fourier Transform imaging showed that Pt-nanoparticles (1.5 nm diameter) had no clear (111) crystal-planes, while larger nanoparticles had clear (111) crystal-planes. X-ray Photo-electron Spectroscopy demonstrated that unloaded nanosheets were composed of MnO2 with a high number of oxygen vacancies (Vo/Mn 0.4). Loading with 7.0 nm Pt-nanoparticles induced a change to Mn2O3, while loading with 1.5 nm nanoparticles increased the number of vacancies (Vo/Mn 1.2). Nanosheets loaded with 3.0 nm Pt-nanoparticles possessed similarly high catalytic activities as Pt-single-atoms. However, loading with 1.5 nm or 7.0 nm Pt-nanoparticles yielded lower catalytic activities. A model is proposed explaining the low catalytic activity of under- and over-sized Pt-nanoparticles as compared with intermediately-sized (3.0 nm) Pt-nanoparticles and single-atoms. Herewith, catalytic activities of hybrid-nanozymes composed of single-atoms and intermediately-sized nanoparticles are put a par, as confirmed here with respect to bacterial biofilm eradication. This conclusion facilitates a balanced choice between using Pt-single-atoms or nanoparticles in further development and application of hybrid-nanozymes.
RESUMO
BACKGROUND: Right ventricular (RV) systolic dysfunction has been identified as a prognostic marker for adverse clinical events in patients presenting with acute pulmonary embolism (PE). However, challenges exist in identifying RV dysfunction using conventional echocardiography techniques. Strain echocardiography is an evolving imaging modality which measures myocardial deformation and can be used as an objective index of RV systolic function. This study evaluated RV Global Longitudinal Strain (RVGLS) in patients with intermediate risk PE as a parameter of RV dysfunction, and compared to traditional echocardiographic and CT parameters evaluating short-term mortality. METHODS: Retrospective single center cohort study of 251 patients with intermediate-risk PE between 2010 and 2018. The primary outcome was all-cause mortality at 30 days. Statistical analysis evaluated each parameter comparing survivors versus non-survivors at 30 days. Receiver operating characteristic (ROC) curves and Kaplan-Meier curves were used for comparison of the two cohorts. RESULTS: Altogether 251 patients were evaluated. Overall mortality rate was 12.4%. Utilizing an ROC curve, an absolute cutoff value of 17.7 for RVGLS demonstrated a sensitivity of 93% and specificity of 70% for observed 30-day mortality. Individuals with an RVGLS ≤17.7 had a 25 times higher mortality rate than those with RVGLS above 17.7 (HR 25.24, 95% CI = 6.0-106.4, p < .001). Area under the curve was (.855), RVGLS outperformed traditional echocardiographic parameters, CT findings, and cardiac biomarkers on univariable and multivariable analysis. CONCLUSIONS: Reduced RVGLS values on initial echocardiographic assessment of patients with intermediate-risk PE identified patients at higher risk for mortality at 30 days.
Assuntos
Embolia Pulmonar , Disfunção Ventricular Direita , Humanos , Deformação Longitudinal Global , Estudos Retrospectivos , Estudos de Coortes , Volume Sistólico , Embolia Pulmonar/complicações , Função Ventricular Direita , PrognósticoRESUMO
BACKGROUND: LV geometry with shape index (SI) and eccentricity index (EI) measured by myocardial perfusion positron emission tomography/computed tomography (PET/CT) may allow the evaluation of left ventricular (LV) adverse remodeling. This first study aims to explore the relationship of SI and EI values acquired by Nitrogen-13 ammonia PET/CT in patients with normal perfusion, ischemia, and myocardial infarction. And evaluate the correlations between the variables of LV geometry, and with the variables of LV function. METHODS AND RESULTS: One hundred and forty patients who underwent an electrocardiogram (ECG)-gated PET/CT were selected and classified into 4 groups according to ischemia or infarction burden (normal perfusion, mild ischemia, moderate-severe ischemia, and infarction). The variables were automatically retrieved using dedicated software (QPS/QGS; Cedars-Sinai, Los Angeles, CA, USA). On multicomparison analysis (one-way ANOVA and Dunnett's Test), subjects in the infarction group had significant higher values of SI end-diastolic rest (P < 0.001), and stress (P = 0.003), SI end-systolic rest (P = 0.002) and stress (P < 0.001) as well as statistically significant lower values of EI rest (P < 0.001) and stress (P < 0.001) when compared with all other groups. Regarding Pearson correlation, in the infarcted group all the variables of SI and EI were significantly correlated (P < 0.001) with strong correlation coefficients (>0.60). SI end-systolic correlated significantly with the variables of LV function independently of the group of patients (P < 0.05). CONCLUSIONS: Shape and eccentricity indices differ in patients with myocardial infarction as compared to patients with ischemia or normal perfusion. This encourage further research in their potential for detecting LV adverse remodeling.
Assuntos
Amônia , Eletrocardiografia , Ventrículos do Coração , Infarto do Miocárdio , Isquemia Miocárdica , Imagem de Perfusão do Miocárdio , Radioisótopos de Nitrogênio , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Humanos , Masculino , Feminino , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/fisiopatologia , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Idoso , Imagem de Perfusão do Miocárdio/métodos , Ventrículos do Coração/diagnóstico por imagem , Isquemia Miocárdica/diagnóstico por imagem , Isquemia Miocárdica/fisiopatologia , Compostos Radiofarmacêuticos , Técnicas de Imagem de Sincronização Cardíaca , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/fisiopatologia , Reprodutibilidade dos TestesRESUMO
The longevity of current joint replacements is limited by aseptic loosening, which is the primary cause of non-infectious failure for hip, knee, and ankle arthroplasty. Aseptic loosening is typically caused either by osteolysis from particulate wear, or by high shear stresses at the bone-implant interface from over-constraint. Our objective was to demonstrate feasibility of a compliant intramedullary stem that eliminates over-constraint without generating particulate wear. The compliant stem is built around a compliant mechanism that permits rotation about a single axis. We first established several models to understand the relationship between mechanism geometry and implant performance under a given angular displacement and compressive load. We then used a neural network to identify a design space of geometries that would support an expected 100-year fatigue life inside the body. We additively manufactured one representative mechanism for each of three anatomic locations, and evaluated these prototypes on a KR-210 robot. The neural network predicts maximum stress and torsional stiffness with 2.69% and 4.08% error respectively, relative to finite element analysis data. We identified feasible design spaces for all three of the anatomic locations. Simulated peak stresses for the three stem prototypes were below the fatigue limit. Benchtop performance of all three prototypes was within design specifications. Our results demonstrate the feasibility of designing patient- and joint-specific compliant stems that address the root causes of aseptic loosening. Guided by these results, we expect the use of compliant intramedullary stems in joint reconstruction technology to increase implant lifetime.
Assuntos
Artroplastia de Substituição , Humanos , Interface Osso-ImplanteRESUMO
BACKGROUND: The appropriate amount of cementation at the time of reverse total shoulder arthroplasty with significant proximal bone loss or resection is unknown. Extensive cementation of a humeral prosthesis makes eventual revision arthroplasty more challenging, increasing the risk of periprosthetic fracture. We analyzed the degree of subsidence and torque tolerance of humeral components undergoing standard cementation technique vs. our reduced polymethyl methacrylate (PMMA) protocol. Reduced cementation may provide sufficient biomechanical stability to resist physiologically relevant loads, while still permitting a clinically attainable torque for debonding the prosthesis. METHODS: A total of 12 cadaveric humeri (6 matched pairs) underwent resection of 5 cm of bone distal to the greater tuberosity. Each pair of humeri underwent standard humeral arthroplasty preparation followed by either cementation using a 1.5-cm PMMA sphere at a location 3 cm inferior to the porous coating or standard full stem cementation. A 6-degree-of-freedom robot was used to perform all testing. Each humeral sample underwent 200 cycles of abduction, adduction, and forward elevation while being subjected to a physiologic compression force. Next, the samples were fixed in place and subjected to an increasing torque until implant-cement separation or failure occurred. Paired t tests were used to compare mean implant subsidence vs. a predetermined 5-mm threshold, as well as removal torque in matched samples. RESULTS: Fully and partially cemented implants subsided 0.49 mm (95% CI 0.23-0.76 mm) and 1.85 mm (95% CI 0.41-3.29 mm), respectively, which were significantly less than the predetermined 5-mm threshold (P < .001 and P < .01, respectively). Removal torque between fully cemented stems was 45.22 Nm (95% CI 21.86-68.57 Nm), vs. 9.26 Nm (95% CI 2.59-15.93 Nm) for partially cemented samples (P = .021). Every fully cemented humerus fractured during implant removal vs. only 1 in the reduced-cementation group. The mean donor age in our study was 76 years (range, 65-80 years). Only 1 matched pair of humeri belonged to a female donor with comorbid osteoporosis. The fractured humerus in the partially cemented group belonged to that donor. CONCLUSION: Partially and fully cemented humeral prostheses had subsidence that was significantly less than 5 mm. Partially cemented stems required less removal torque for debonding of the component from the cement mantle. In all cases, removal of fully cemented stems resulted in humeral fracture. Reduced cementation of humeral prostheses may provide both sufficient biomechanical stability and ease of future component removal.
Assuntos
Artroplastia do Ombro , Cimentos Ósseos , Cadáver , Úmero , Desenho de Prótese , Prótese de Ombro , Humanos , Artroplastia do Ombro/métodos , Fenômenos Biomecânicos , Úmero/cirurgia , Idoso , Feminino , Masculino , Cimentação , Articulação do Ombro/cirurgia , Articulação do Ombro/fisiopatologia , Idoso de 80 Anos ou mais , Polimetil MetacrilatoRESUMO
Background. Tricuspid regurgitation (TR) is a high-prevalence disease associated with poor quality of life and mortality. This quantitative patient preference study aims to identify TR patients' perspectives on risk-benefit tradeoffs. Methods. A discrete-choice experiment was developed to explore TR treatment risk-benefit tradeoffs. Attributes (levels) tested were treatment (procedure, medical management), reintervention risk (0%, 1%, 5%, 10%), medications over 2 y (none, reduce, same, increase), shortness of breath (none/mild, moderate, severe), and swelling (never, 3× per week, daily). A mixed logit regression model estimated preferences and calculated predicted probabilities. Relative attribute importance was calculated. Subgroup analyses were performed. Results. An online survey was completed by 150 TR patients. Shortness of breath was the most important attribute and accounted for 65.8% of treatment decision making. The average patients' predicted probability of preferring a "procedure-like" profile over a "medical management-like" profile was 99.7%. This decreased to 78.9% for a level change from severe to moderate in shortness of breath in the "medical management-like" profile. Subgroup analysis confirmed that patients older than 64 y had a stronger preference to avoid severe shortness of breath compared with younger patients (P < 0.02), as did severe or worse TR patients relative to moderate. New York Heart Association class I/II patients more strongly preferred to avoid procedural reintervention risk relative to class III/IV patients (P < 0.03). Conclusion. TR patients are willing to accept higher procedural reintervention risk if shortness of breath is alleviated. This risk tolerance is higher for older and more symptomatic patients. These results emphasize the appropriateness of developing TR therapies and the importance of addressing symptom burden. Highlights: This study provides quantitative patient preference data from clinically confirmed tricuspid regurgitation (TR) patients to understand their treatment preferences.Using a targeted literature search and patient, physician, and Food and Drug Administration feedback, a cross-sectional survey with a discrete-choice experiment that focused on 5 of the most important attributes to TR patients was developed and administered online.TR patients are willing to accept higher procedural reintervention risk if shortness of breath is alleviated, and this risk tolerance is higher for older and more symptomatic patients.
RESUMO
Assessment of volume status in hospitalized patients with heart failure is a critically important diagnostic skill that clinicians utilize frequently. However, accurate assessment is challenging and there is often significant inter-provider disagreement. This review serves as an appraisal of current methods of volume assessment amongst different categories of evaluation including patient history, physical exam, laboratory analysis, imaging, and invasive procedures. Within each category, this review highlights methods that are particularly sensitive or specific, or those that carry impactful positive or negative likelihood ratios. Utilization of the information that this review provides will allow clinicians to determine volume status of hospitalized heart failure patients more accurately and more precisely in order to provide appropriate and effective therapies.
RESUMO
Adverse cardiac events after laparoscopic bariatric surgery are rare, yet preoperative cardiology evaluation and testing remain common, resulting in the overuse of cardiac testing in low-risk patients. Our objective was to assess the frequency of, and factors associated with, overuse of preoperative cardiac testing in patients at low cardiac risk before laparoscopic bariatric surgery. We retrospectively reviewed data from 1,094 adult patients who underwent laparoscopic bariatric surgery at our institution from January 1, 2015, through December 31, 2019. The cardiac risk was determined using the Revised Cardiac Risk Index (RCRI) and the National Surgical Quality Improvement Program Myocardial Infarction and Cardiac Arrest (NSQIP MICA) risk model. Multivariate logistic regression was used to evaluate risk factors associated with the overuse of cardiac testing in low-risk patients. Overall, 1,059 patients (96.8%) were estimated to be at low cardiac risk by the RCRI, and 1,094 (100%) were at low cardiac risk by NSQIP MICA. A total of 587 patients (51.8%) were referred to cardiology for preoperative evaluation, and 643 patients (56.7%) underwent one or more preoperative cardiac tests. Factors associated with overuse of preoperative cardiac testing in low-risk patients included preoperative cardiology referral (adjusted odds ratio 37.2, 95% confidence interval 25.3 to 54.7) and patient age (adjusted odds ratio 1.05, 95% confidence interval 1.03 to 1.07). Overuse of preoperative cardiac testing was common in patients at low cardiac risk before laparoscopic bariatric surgery. Preoperative referral to cardiology was the most significant risk factor associated with the overuse of preoperative cardiac testing. Application of risk models such as the RCRI or NSQIP MICA at the time of bariatric program enrollment may reduce unnecessary preoperative cardiac testing in low-risk patients.
Assuntos
Cirurgia Bariátrica , Laparoscopia , Adulto , Humanos , Estudos Retrospectivos , Cirurgia Bariátrica/efeitos adversos , Fatores de Risco , Complicações Pós-Operatórias/etiologia , Laparoscopia/efeitos adversos , Laparoscopia/métodos , Medição de Risco/métodosRESUMO
BACKGROUND: The past few decades have seen rapid advancements in exoskeleton technology, with a considerable shift towards applications involving users with gait pathologies. Commercial devices from ReWalk, Ekso Bionics, and Indego, mainly designed for rehabilitation purposes, have inspired the development of many research platforms aimed at extending capabilities for use as safe and effective personal mobility devices. The 2016 Cybathlon featured an impressive demonstration of exoskeletons designed to enable mobility for individuals with spinal cord injury, however, not a single team completed every task and only two completed the stairs. Major improvements were showcased at the 2020 Cybathlon, with seven of the nine teams completing a similar set of tasks. Team IHMC built upon its silver-medal success from 2016 with an upgraded device, Quix. METHODS: Quix features several notable improvements including an additional powered degree of freedom for hip ab/adduction to laterally shift the device and reduce user effort while walking, custom-tailored cuffs and soft goods based on 3D body scans to optimize user comfort, and a streamlined testing pipeline for online tuning of gait parameters. RESULTS: Team IHMC finished in fourth place behind the teams from EPFL and Angel Robotics. Although we suffered from a considerably slower flat-ground walking speed, our pilot reported marked improvements in overall effort, comfort, and ease-of-use compared to our previous device. CONCLUSIONS: Clear progress in exoskeleton development has been exhibited since the inaugural Cybathlon, with tasks involving rough terrain, stairs, and ramps now posing little threat to most of the competitors. As a result, the layout of the powered exoskeleton course will likely undergo significant modifications to further push the devices towards suitability for personal everyday use. The current tasks do not address the issue of donning and doffing, nor do they simulate a scenario similar to maneuvering a kitchen to prepare a meal, for example. An additional limitation that may be more difficult to test in a competition setting is the required upper-body effort to manipulate the device in an effective manner.
Assuntos
Exoesqueleto Energizado , Traumatismos da Medula Espinal , Marcha , Humanos , Prata , Traumatismos da Medula Espinal/reabilitação , CaminhadaRESUMO
BACKGROUND: The American College of Cardiology Core Cardiovascular Training Statement (COCATS) defined echocardiography core competencies and set the minimum recommend number of echocardiograms to perform (150) and interpret (300) for independent practice in echocardiography (level 2 training). Fellows may lack exposure to key pathologies that are relatively infrequent, however, even when achieving an adequate number of studies performed and interpreted. We hypothesized that cardiology fellows would lack exposure to 1 or more cardiac pathologies related to core competencies in COCATS when performing and interpreting the minimum recommend number of studies for level 2 training. METHODS: We retrospectively reviewed 11,250 reports from consecutive echocardiograms interpreted (7,500) and performed (3,750) by 25 cardiology fellows at a University tertiary referral hospital who graduated between 2015 and 2019. The first 300 echocardiograms interpreted and the first 150 echocardiograms performed by each fellow were included in the analysis. Echocardiography reports were reviewed for cardiac pathologies relating to core competencies defined in COCATS. RESULTS: All 25 fellows lacked exposure to 1 or more cardiac pathologies related to echocardiography core competencies despite meeting COCATS minimum recommended numbers for echocardiograms performed and interpreted. Pathologies for which 1 or more fellows encountered 0 cases despite meeting the minimum recommended numbers for both echocardiograms performed and interpreted included: pericardial constriction (16/25 fellows), aortic dissection (15/25 fellows), pericardial tamponade (4/25 fellows), valvular mass/thrombus (2/25 fellows), prosthetic valve dysfunction (1/25 fellows), and cardiac chamber mass/thrombus (1/25 fellows). CONCLUSIONS: Cardiology fellows who completed the minimum recommend number of echocardiograms performed and interpreted for COCATS level 2 training frequently lacked exposure to cardiac pathologies, even in a University tertiary referral hospital setting. These data suggest that fellowship programs should monitor pathology case counts for each fellow in training, in addition to the minimum recommend number of echocardiograms defined by COCATS, to ensure competency for independent practice in echocardiography.
Assuntos
Cardiologia , Cardiopatias Congênitas , Cardiologia/educação , Competência Clínica , Ecocardiografia , Humanos , Estudos Retrospectivos , Estados UnidosRESUMO
This study aimed to assess long-term resource utilization and outcomes in patients with acute chest pain who underwent coronary computed tomography angiography (CCTA) and stress echocardiography (SE). This was a retrospective, propensity-matched analysis of health insurance claims data for a national sample of privately insured patients over the period January 1, 2011, to December 31, 2014. There were 3,816 patients matched 1:1 who received either CCTA (nâ¯=â¯1,908) or SE (nâ¯=â¯1,908). Patients were seen in the emergency department (ED) between January 1, 2011, and December 31, 2011 with a primary diagnosis of chest pain and received either CCTA or SE within 72 hours as the first noninvasive test and maintained continuous enrollment in the database from the time of the ED encounter through December 31, 2014. All individual patient data were censored at 3 years. Compared with SE, CCTA was associated with higher odds of downstream cardiac catheterization (9.9% vs 7.7%, adjusted odds ratio [AOR] 1.28, 95% confidence interval (CI) 1.00 to 1.63), future noninvasive testing (27.7% vs 22.3%, AOR 1.22, 95% CI 1.05 to 1.42), and return ED visits or hospitalization for chest pain at 3 years (33.1% vs 24.2%, AOR 1.37, 95% CI 1.19 to 1.59). There were no statistically significant differences in new statin use (15.5% vs 14.9%, AOR 1.04, 95% CI 0.85 to 1.28), coronary revascularization (2.7% vs 2.2%, AOR 1.25, 95% CI 0.77 to 2.01) or hospitalization for acute myocardial infarction (0.9% vs 0.9%, AOR 0.96, 95% CI 0.47 to 1.99). In conclusion, in patients who present to the ED with chest pain, CCTA is associated with increased downstream resource utilization compared with SE with no differences in long-term cardiovascular outcomes.
Assuntos
Cateterismo Cardíaco/estatística & dados numéricos , Dor no Peito/fisiopatologia , Angiografia por Tomografia Computadorizada/métodos , Doença da Artéria Coronariana/diagnóstico , Ecocardiografia sob Estresse/métodos , Infarto do Miocárdio/epidemiologia , Revascularização Miocárdica/estatística & dados numéricos , Readmissão do Paciente/estatística & dados numéricos , Dor no Peito/etiologia , Angiografia Coronária , Doença da Artéria Coronariana/complicações , Serviço Hospitalar de Emergência , Feminino , Seguimentos , Recursos em Saúde , Hospitalização , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Pontuação de Propensão , Estudos RetrospectivosRESUMO
Bacterial biofilms occur in many natural and industrial environments. Besides bacteria, biofilms comprise over 70 wt% water. Water in biofilms occurs as bound- or free-water. Bound-water is adsorbed to bacterial surfaces or biofilm (matrix) structures and possesses different Infra-red and Nuclear-Magnetic-Resonance signatures than free-water. Bound-water is different from intra-cellularly confined-water or water confined within biofilm structures and bacteria are actively involved in building water-filled structures by bacterial swimmers, dispersion or lytic self-sacrifice. Water-filled structures can be transient due to blocking, resulting from bacterial growth, compression or additional matrix formation and are generally referred to as "channels and pores." Channels and pores can be distinguished based on mechanism of formation, function and dimension. Channels allow transport of nutrients, waste-products, signalling molecules and antibiotics through a biofilm provided the cargo does not adsorb to channel walls and channels have a large length/width ratio. Pores serve a storage function for nutrients and dilute waste-products or antimicrobials and thus should have a length/width ratio close to unity. The understanding provided here on the role of water in biofilms, can be employed to artificially engineer by-pass channels or additional pores in industrial and environmental biofilms to increase production yields or enhance antimicrobial penetration in infectious biofilms.
Assuntos
Anti-Infecciosos , Água , Antibacterianos , Bactérias/genética , BiofilmesRESUMO
Biomaterial-associated infections can occur any time after surgical implantation of biomaterial implants and limit their success rates. On-demand, antimicrobial release coatings have been designed, but in vivo release triggers uniquely relating with infection do not exist, while inadvertent leakage of antimicrobials can cause exhaustion of a coating prior to need. Here, we attach magnetic-nanoparticles to a biomaterial surface, that can be pulled-off in a magnetic field through an adhering, infectious biofilm. Magnetic-nanoparticles remained stably attached to a surface upon exposure to PBS for at least 50 days, did not promote bacterial adhesion or negatively affect interaction with adhering tissue cells. Nanoparticles could be magnetically pulled-off from a surface through an adhering biofilm, creating artificial water channels in the biofilm. At a magnetic-nanoparticle coating concentration of 0.64 mg cm-2, these by-pass channels increased the penetrability of Staphylococcus aureus and Pseudomonas aeruginosa biofilms towards different antibiotics, yielding 10-fold more antibiotic killing of biofilm inhabitants than in absence of artificial channels. This innovative use of magnetic-nanoparticles for the eradication of biomaterial-associated infections requires no precise targeting of magnetic-nanoparticles and allows more effective use of existing antibiotics by breaking the penetration barrier of an infectious biofilm adhering to a biomaterial implant surface on-demand.
Assuntos
Antibacterianos , Nanopartículas de Magnetita , Antibacterianos/farmacologia , Materiais Biocompatíveis , Biofilmes , Staphylococcus aureusRESUMO
Photothermal nanoparticles can be used for non-antibiotic-based eradication of infectious biofilms, but this may cause collateral damage to tissue surrounding an infection site. In order to prevent collateral tissue damage, we encapsulated photothermal polydopamine-nanoparticles (PDA-NPs) in mixed shell polymeric micelles, composed of stealth polyethylene glycol (PEG) and pH-sensitive poly(ß-amino ester) (PAE). To achieve encapsulation, PDA-NPs were made hydrophobic by electrostatic binding of indocyanine green (ICG). Coupling of ICG enhanced the photothermal conversion efficacy of PDA-NPs from 33% to 47%. Photothermal conversion was not affected by micellar encapsulation. No cytotoxicity or hemolytic effects of PEG-PAE encapsulated PDA-ICG-NPs were observed. PEG-PAE encapsulated PDA-ICG-NPs showed good penetration and accumulation in a Staphylococcus aureus biofilm. Penetration and accumulation were absent when nanoparticles were encapsulated in PEG-micelles without a pH-responsive moiety. PDA-ICG-NPs encapsulated in PEG-PAE-micelles found their way through the blood circulation to a sub-cutaneous infection site after tail-vein injection in mice, yielding faster eradication of infections upon near-infrared (NIR) irradiation than could be achieved after encapsulation in PEG-micelles. Moreover, staphylococcal counts in surrounding tissue were reduced facilitating faster wound healing. Thus, the combined effect of targeting and localized NIR irradiation prevented collateral tissue damage while eradicating an infectious biofilm.
RESUMO
BACKGROUND: The CADILLAC risk score was developed to identify patients at low risk for adverse cardiovascular events following ST elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PPCI). METHODS: We performed a single center retrospective review of STEMI hospitalizations treated with PPCI from 2014 to 2018. Patients were stratified using the CADILLAC risk score into low risk, intermediate risk and high risk groups. Patients presenting with cardiac arrest or cardiogenic shock were excluded from the study. The primary outcome was adverse clinical events during initial hospitalization. Secondary outcomes were adverse clinical events at 30 days and 1 year following index hospitalization. RESULTS: The study included 341 patients. Compared to patients with a low CADILLAC score, adverse clinical events were similar in the intermediate risk group during hospitalization (OR 1.23, CI 0.37-4.05, p 0.733) and at 30 days (OR 2.27, CI 0.93-5.56, p 0.0733) while adverse clinical events were significantly elevated in the high risk group during hospitalization (OR 4.75, CI 1.91-11.84, p 0.0008) and at 30 days (OR 8.73, CI 4.02-18.96, p < 0.0001). At 1 year follow-up, compared to the low risk CADILLAC group (9.4% adverse clinical event rate), cumulative adverse clinical events were significantly higher in the intermediate risk group (22.9% event rate, OR 2.86, CI 1.39-5.89, p 0.0044) and in the elevated risk group (58.6% event rate, OR 13.67, CI 6.81-27.43, p < 0.0001). The mortality rate was 0% for patients defined at low risk by CADILLAC score during hospitalization, as well up to 1 year follow up. On receiver operating curve analysis, discrimination of in-hospital adverse clinical events was fair using CADILLAC (C = 0.66, odds ratio 1.18; 95% CI 1.04-1.33; p = 0.0064) with somewhat better discrimination at 30-day follow-up (C = 0.719) and 1-year follow-up (C = 0.715). CONCLUSION: Patients defined as low risk by the CADILLAC score following a STEMI were associated with lower mortality and adverse clinical event rates during hospitalization and up to 1 year following STEMI when compared to those with an intermediate or high CADILLAC score.
Assuntos
Mortalidade Hospitalar , Medição de Risco , Fatores de Risco , Infarto do Miocárdio com Supradesnível do Segmento ST/complicações , Idoso , Doenças Cardiovasculares/etiologia , Feminino , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Intervenção Coronária Percutânea , Estudos Retrospectivos , Infarto do Miocárdio com Supradesnível do Segmento ST/mortalidade , Infarto do Miocárdio com Supradesnível do Segmento ST/terapia , Índice de Gravidade de DoençaRESUMO
AbstractThe leaf economics spectrum ranges from cheap, short-lived leaves to expensive, long-lived leaves. Species with low leaf mass per area (LMA) and short leaf life span tend to be fast growing and shade intolerant (early successional), whereas species with high LMA and long leaf life span tend to be slow growing and shade tolerant (late successional). However, we have limited understanding of how different leaf mass components (e.g., metabolically active photosynthetic components vs. structural toughness components) contribute to variation in LMA and other leaf economics spectrum traits. Here, we develop a model of plant community dynamics in which species differ in just two traits, photosynthetic and structural LMA components, and we identify optimal values of these traits for early- and late-successional species. Most of the predicted increase in LMA from early- to late-successional species was due to structural LMA. Photosynthetic LMA did not differ consistently between early- and late-successional species, but the photosynthetic LMA to structural LMA ratio declined from early- to late-successional species. Early-successional species had high rates of instantaneous return on leaf mass investment, whereas late-successional species had high lifetime return. Our results provide theoretical support for the primary role of structural (rather than photosynthetic) LMA variation in driving relationships among leaf economics spectrum traits.
Assuntos
Folhas de Planta , Plantas , Fenótipo , FotossínteseRESUMO
BACKGROUND: As surgical techniques evolve and patient outcomes improve over time, a renewed analysis of the cardiac risk of noncardiac surgeries is needed. The goal of this study was to investigate and categorize the cardiac risk of elective noncardiac surgeries. METHODS: This was a cohort study of surgical data and outcomes from the 2018 National Surgical Quality Improvement Program Participant Use Data File; 807,413 cases were analyzed after excluding non-elective, emergent, and cardiac surgeries. Postoperative major adverse cardiac events (MACE) were defined as 30-day all-cause mortality, myocardial infarction, or cardiac arrest. According to their 95% confidence intervals (CI) for postoperative MACE, surgeries were categorized as low risk (95% CI <1%), intermediate risk (95% CI above and below 1%), or elevated risk (95% CI ≥1%). Multivariable logistic regression analyses were performed to determine differences in the odds for postoperative MACE for the intermediate- and elevated-risk categories relative to the low-risk category while controlling for several risk factors of prognostic importance. RESULTS: Postoperative MACE occurred in 4047/807,413 cases (0.50%), including in 1708/667,735 (0.26%) of the low-risk category, in 516/53,499 (0.96%) of the intermediate-risk category, and in 1823/86,179 (2.12%) of the elevated-risk category. The elevated-risk category accounted for 10.7% of total procedures and 45.1% of total postoperative MACE. Compared with the low-risk category, the multivariable adjusted risk of postoperative MACE was increased in the intermediate-risk category (adjusted odds ratio 2.35; 95% CI, 2.12-2.62) and the elevated-risk category (adjusted odds ratio 3.15; 95% CI, 2.92-3.39). CONCLUSION: Categorization of noncardiac surgeries according to cardiac risk may help to identify populations who are most likely to benefit from preoperative cardiac evaluation when indicated.