Search

Design and preparation of layered composite materials alternating between nucleic acids and proteins has been elusive due to limitations in occurrence and geometry of interaction sites in natural biomolecules. We report the design and kinetically controlled stepwise synthesis of a nano-sandwich composite by programmed noncovalent association of protein, DNA and RNA modules. A homo-tetramer protein core was introduced to control the self-assembly and precise positioning of two RNA-DNA hybrid nanotriangles in a co-parallel sandwich arrangement. Kinetically favored self-assembly of the circularly closed nanostructures at the protein was driven by the intrinsic fast folding ability of RNA corner modules which were added to precursor complex of DNA bound to the protein. The 3D architecture of this first synthetic protein-RNA-DNA complex was confirmed by fluorescence labeling and cryo-electron microscopy studies. The synthesis strategy for the nano-sandwich composite provides a general blueprint for controlled noncovalent assembly of complex supramolecular architectures from protein, DNA and RNA components, which expand the design repertoire for bottom-up preparation of layered biomaterials.

Meniscal tears are common knee injuries with limited endogenous healing capacity. This study aimed to investigate the association between the timing and administration of preoperative intra-articular corticosteroid injections (CSIs) and the risk of subsequent meniscectomy following meniscus repair. Using a national insurance claims database, patients aged 18–40 years undergoing meniscus repair within six months of tear diagnosis were studied. Patients were categorized based on whether they received preoperative CSIs within three intervals prior to repair. Multivariable logistic regression was used to analyze the risk of follow-up meniscectomy while controlling for various patient-related variables. Among 5,390 patients meeting inclusion criteria, 201 received preoperative CSIs. The CSI group was older and had higher rates of diabetes, obesity, and knee osteoarthritis. The overall rate of follow-up meniscectomy did not differ between groups. However, CSIs performed within one month prior to repair were associated with significantly higher odds of subsequent meniscectomy compared to CSIs performed between three and six months prior. Obesity, tobacco use, and knee osteoarthritis were also independently associated with higher risk, while increasing age was associated with lower risk. The study highlights an increased risk of repair failure requiring follow-up meniscectomy for patients receiving intra-articular CSIs within one month prior to meniscus repair. These findings suggest caution when considering CSIs as a treatment option for patients scheduled for meniscus repair. Further research is needed to establish optimal timing guidelines for CSIs in relation to meniscus repair and to understand the underlying mechanisms. [ABSTRACT FROM AUTHOR]

Existing primary evidence comparing fibular intramedullary fixation (IMF) with traditional plate fixation (PF) for the treatment of distal fibular fractures remains limited by modest sample sizes. Using a large national database, this study aims to compare use rates, fracture patterns, patient characteristics, time to surgery, complication rates, and cost between fibular IMF and PF within the United States. Adults treated with fibular IMF or PF between October 2015 and October 2021 were identified within the PearlDiver Database. The ratio of IMF‐treated to PF‐treated patients was tracked temporally to compare use rates. Fracture patterns were determined using fracture diagnoses within one‐month preceding surgery. Further comparisons of IMF‐ and PF‐treated groups only included patients with at least 12 months of follow‐up, and patients with upper tibia or tibia shaft fractures were excluded. An analysis of cohorts matched at a 1 : 4 (IMF: PF) ratio to control for risk factors was performed to compare time to surgery, complication rates (infection, nonunion, malunion, revision, hardware removal, pulmonary embolism, and deep vein thrombosis), and cost. 39329 patients (2294 IMF and 37035 PF) were identified. IMF use trended upwards relative to PF use over time. Tibia and fibula shaft fractures were the most common injuries in IMF patients versus bimalleolar and trimalleolar fractures in PF patients. A higher proportion of IMF patients had open fractures. IMF patients were younger, with higher mean ECI, fewer female patients, and higher rates of CKD. Percutaneous approaches were more common among IMF patients. There were no significant differences in time to surgery or complication rates. IMF was less costly. The popularity of IMF trended upwards across the study period. IMF was used more commonly in injuries involving higher energy trauma and soft tissue disruption. Overall, IMF patients were younger with more comorbidities. When used in similar populations, IMF appears to be a cost‐effective alternative to PF. [ABSTRACT FROM AUTHOR]

Objective: This novel pilot study constructs a social deprivation index (SDI) and utilizes an area deprivation index (ADI) to evaluate the link between social determinants of health and rhinology patient experiences. Methods: Adult patients undergoing outpatient care of chronic rhinitis and chronic rhinosinusitis at a tertiary academic medical center were recruited to participate in a telephone survey assessing symptoms, social/emotional consequences of disease, and barriers to care on a 5‐point Likert scale. Sociodemographic characteristics were utilized to rate SDI on an 8‐point scale. ADI was obtained by area code of residence. Ordered logistic regression was used to examine associations between the SDI/ADI and perceptions of rhinology care. Results: Fifty patients were included. Individuals with higher SDI scores (i.e., more socially deprived) experienced more severe nasal congestion (p =.007). Furthermore, higher national ADI correlated with increased severity of smell changes (p =.050) and facial pressure (p =.067). No association was seen between either deprivation index and global/psychiatric symptoms. While no correlations were found between higher SDI and difficulties with the costs of prescriptions, rhinologist's visits, or saline, higher SDI was correlated with decreased difficulty with surgery costs (p =.029), and individuals with higher national ADI percentile had increased difficulties obtaining nasal saline (p =.029). Conclusion: Worse social deprivation is associated with difficulties obtaining saline rinses and increased severity of nasal/sinus symptoms in an urban, underserved, majority‐Black population. These findings suggest social factors affect access to and quality of rhinology care in a complex and nuanced way and highlight the need for a specific SDI to further study social determinants of health in rhinology. Level of Evidence: 2c. We construct a social deprivation index and utilize an area deprivation index to study social determinants of health and rhinology patient experiences. Worse social deprivation is associated with difficulties obtaining the most basic of rhinology care—saline rinses, as well as increased severity of nasal/sinus symptoms in an urban, underserved, majority‐Black population. [ABSTRACT FROM AUTHOR]

The reliable generation of smooth muscle cells is important for a number of tissue engineering applications. Human mesenchymal stem cells (MSCs) are a promising progenitor of smooth muscle, with high expression of smooth muscle markers observed in a fraction of isolated cells, which can be increased by introduction of soluble supplements that direct differentiation. Here we demonstrate a new micropatterning technique, where peptides of different ligand affinity can be microcontact printed onto an inert background, to explore MSC differentiation to smooth muscle through controlled biochemical and biophysical cues alone. Using copper-catalyzed alkyne-azide cycloaddition (CuAAC), we patterned our surfaces with RGD peptide ligands-both a linear peptide with low integrin affinity and a cyclic version with high integrin affinity-for the culture of MSCs in shapes with various aspect ratios. At low aspect ratio, ligand affinity is a prime determinant for smooth muscle differentiation, while at high aspect ratio, ligand affinity has less of an effect. Pathway analysis reveals a role for focal adhesion turnover, Rac1, RhoA/ROCK, and calpain during smooth muscle differentiation of MSCs in response to cell shape and the affinity of the cell adhesion interface. Controlling integrin-ligand affinity at the biomaterials interface is important for mediating adhesion but may also prove useful for directing smooth muscle myogenesis. Peptide patterning enables the systematic investigation of single to multiple peptides derived from any protein, at different densities across a biomaterials surface, which has the potential to direct multiple MSC differentiation outcomes without the need for soluble supplements. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1212-1220, 2016. [ABSTRACT FROM AUTHOR]

Examines two species of Acuaria in passerine birds from the Area de Conservacion Guanacaste, Costa Rica. Anterior portion of the glandular esophagus; Difference of the two species from A. pattoni; Measurement of spicule.