Non-Fusion Versus Fusion Surgery in Pediatric Idiopathic Scoliosis: What Trade-Offs in Outcomes Are Acceptable for the Patient and Family?

BACKGROUND: Vertebral body tethering and other non-fusion techniques for the treatment of pediatric idiopathic scoliosis are increasing in popularity. There is limited physician consensus on this topic as the result of a paucity of published data regarding which patients most benefit from non-fusion strategies. Thus, much of the decision-making is left to patients and parents, who must select a treatment based on their goals and values and the information available from health-care providers, the internet, and social media. We sought to understand patient and family preferences regarding the attributes of fusion versus non-fusion surgery that drive these choices. METHODS: Patients and families were recruited from 7 pediatric spine centers and were asked to complete a survey-based choice experiment that had been jointly developed with the U.S. Food and Drug Administration (FDA) to evaluate patient preferences. Choices between experimentally designed alternatives were analyzed to estimate the relative importance of outcomes and requirements associated with the choice options (attributes). The attributes included appearance, confidence in the planned correction, spinal motion, device failure, reoperation, and recovery period. The inclusion criteria were (1) an age of 10 to 21 years and (2) a diagnosis of adolescent idiopathic scoliosis in patients who were considering, or who had already undergone, treatment with fusion or non-fusion surgery. Preference weights were estimated from the expected changes in choice given changes in the attributes. RESULTS: A total of 344 respondents (124 patients, 92 parents, and 128 parent/patient dyads) completed the survey. One hundred and seventy-three patients were enrolled prior to surgery, and 171 were enrolled after surgery. Appearance and motion were found to be the most important drivers of choice. For the entire cohort, fusion was preferred over non-fusion. For patients who were considering surgery, the most important attributes were preservation of spinal motion and appearance. CONCLUSIONS: Patients and families seeking treatment for idiopathic scoliosis value appearance and preservation of spinal motion and, to a lesser extent, reoperation rates when considering fusion versus non-fusion surgery.

Patient-reported outcome measures for individuals with temporomandibular joint disorders: a systematic review and evaluation.

OBJECTIVE: We used consensus-based, systematic protocols to evaluate the reliability and validity of patient-reported outcome measures (PROMs) for use in documenting treatment outcomes for temporomandibular disorders (TMDs). STUDY DESIGN: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we conducted a focused search of 5 literature databases resulting in a yield of 445 articles that qualified for full-text review. Our review identified 124 PROMs, from which we selected 19 directly related to symptoms of TMD including temporomandibular joint (TMJ) function. RESULTS: We abstracted data on 9 Consensus-based Standards of the selection of health Measurements INstruments (COSMIN) measurement properties and analyzed these data according to COSMIN criteria. Only 3 PROMs provided evidence for at least half of the COSMIN properties: Eight-item Jaw Function Limitations Scale, Oral Health Impact Profile (OHIP)-TMD (OHIP-TMD), and TMJ Ankylosis Specific Quality of Life Questionnaire. Only the OHIP-TMD provided evidence for properties essential to evaluating change over time: reliability, measurement error, and responsiveness. CONCLUSION: We believe these results can alert clinical practitioners to gaps in our knowledge about the most widely used PROMs in TMD practice, and identify topics requiring further study for clinical researchers.

Inclusion of patient-reported outcome instruments in US FDA medical device marketing authorizations.

BACKGROUND: The U.S. Food and Drug Administration encourages the incorporation of the patient voice throughout the medical device total product lifecycle. This study examined the incorporation of patient-reported outcome (PRO) instruments in the evaluation of medical devices over a six-year period. PRO instruments used to inform study endpoints were extracted from the summary documents and clinical trial data of premarket authorizations posted on publicly available FDA databases between October 1, 2014-September 30, 2020. RESULTS: PROs were included in 53% of authorizations, with 34% using PROs as primary and secondary endpoints. This study found that PRO instruments were used in each type of marketing authorization and in all medical specialties examined in this study. CONCLUSIONS: Expanding the current collaborative efforts to develop and modify PRO instruments may help to improve use of PROs in medical device evaluations.

Measuring Patient Preferences at the FDA Center for Devices and Radiological Health: Reflections and Projections.

OBJECTIVES: Patient preference information (PPI) is a way to incorporate the patient voice in the evaluation of medical devices. The US Food and Drug Administration (FDA) Center for Devices and Radiological Health (CDRH) has been working to encourage the voluntary inclusion of PPI throughout the medical device lifecycle for nearly a decade. This article reflects CDRH's efforts to encourage collection of PPI and offers perspectives on the future of PPI in the evaluation of medical devices. METHODS: CDRH regulatory guidance, public meetings, and collaborations relating to PPI were explored. RESULTS: Since 2012 when CDRH issued guidance on how PPI can be used as scientific evidence in the benefit-risk regulatory submission, CDRH has issued 5 subsequent guidance documents expanding on the use of PPI in medical device evaluations. CDRH remains committed to advancing the science and application of PPI in the medical device ecosystem through many collaborations with professional organizations, patient advocacy groups, and academic institutions. By hosting and actively participating in multiple scientific and regulatory public meetings and conferences, CDRH fosters a continuous learning environment where the experience of using PPI in regulatory submissions can be shared. A September 2020 meeting cosponsored by FDA and International Society for Pharmacoeconomics and Outcomes Research (ISPOR) discussed the state of PPI in regulatory applications and beyond. CONCLUSION: This article describes these pivotal events that have helped to increase the use of PPI in medical device evaluation as well as discusses future applications of PPI.

US Food and Drug Administration and Off-Label Use of Metal Expandable Biliary Stents within the Peripheral Vasculature-Update.

In the past, some medical device manufacturers were obtaining marketing clearance for metallic stents indicated for biliary use; however, these devices were being promoted and used in the peripheral vasculature, creating a patient safety problem. The US Food and Drug Administration (FDA) acted in 2006-2008 to help decrease off-label use of metal expandable biliary stents. This communication describes the early and continued efforts of the FDA to address safety concerns relating to off-label use of metal expandable biliary stents and the status of this issue. An analysis of Medical Device Reporting (MDR) data from January 1, 2005, through December 31, 2018, was conducted to determine the percentage of MDR reports associated with off-label use. The percentage was approximately 90% in 2001-2006 and decreased to < 40% a decade later. In reports associated with off-label use, these devices are still associated with death and serious injury; however, the percentage of injury MDR reports associated with off-label device use has trended down since 2007. Whereas 92%-95% of reported serious injuries were with off-label placement in 2005-2007, 43%-79% of injuries were with off-label placement in 2008-2018. Collaborative efforts among the FDA, manufacturers, and physicians appear to have made progress in addressing this issue.

An inexpensive, customizable microscopy system for the automated quantification and characterization of multiple adherent cell types.

Cell quantification assays are essential components of most biological and clinical labs. However, many currently available quantification assays, including flow cytometry and commercial cell counting systems, suffer from unique drawbacks that limit their overall efficacy. In order to address the shortcomings of traditional quantification assays, we have designed a robust, low-cost, automated microscopy-based cytometer that quantifies individual cells in a multiwell plate using tools readily available in most labs. Plating and subsequent quantification of various dilution series using the automated microscopy-based cytometer demonstrates the single-cell sensitivity, near-perfect R2 accuracy, and greater than 5-log dynamic range of our system. Further, the microscopy-based cytometer is capable of obtaining absolute counts of multiple cell types in one well as part of a co-culture setup. To demonstrate this ability, we recreated an experiment that assesses the tumoricidal properties of primed macrophages on co-cultured tumor cells as a proof-of-principle test. The results of the experiment reveal that primed macrophages display enhanced cytotoxicity toward tumor cells while simultaneously losing the ability to proliferate, an example of a dynamic interplay between two cell populations that our microscopy-based cytometer is successfully able to elucidate.

Analysis of decreases in systemic arterial pressure and heart rate in response to the hydrogen sulfide donor sodium sulfide.

The actions of hydrogen sulfide (H2S) on the heart and vasculature have been extensively reported. However, the mechanisms underlying the effects of H2S are unclear in the anesthetized rat. The objective of the present study was to investigate the effect of H2S on the electrocardiogram and examine the relationship between H2S-induced changes in heart rate (HR), mean arterial pressure (MAP), and respiratory function. Intravenous administration of the H2S donor Na2S in the anesthetized Sprague-Dawley rat decreased MAP and HR and produced changes in respiratory function. The administration of Na2S significantly increased the RR interval at some doses but had no effect on PR or corrected QT(n)-B intervals. In experiments where respiration was maintained with a mechanical ventilator, we observed that Na2S-induced decreases in MAP and HR were independent of respiration. In experiments where respiration was maintained by mechanical ventilation and HR was maintained by cardiac pacing, Na2S-induced changes in MAP were not significantly altered, whereas changes in HR were abolished. Coadministration of glybenclamide significantly increased MAP and HR responses at some doses, but methylene blue, diltiazem, and ivabradine had no significant effect compared with control. The decreases in MAP and HR in response to Na2S could be dissociated and were independent of changes in respiratory function, ATP-sensitive K+ channels, methylene blue-sensitive mechanism involving L-type voltage-sensitive Ca2+ channels, or hyperpolarization-activated cyclic nucleotide-gated channels. Cardiovascular responses observed in spontaneously hypertensive rats were more robust than those in Sprague-Dawley rats.NEW & NOTEWORTHY H2S is a gasotransmitter capable of producing a decrease in mean arterial pressure and heart rate. The hypotensive and bradycardic effects of H2S can be dissociated, as shown with cardiac pacing experiments. Responses were not blocked by diltiazem, ivabradine, methylene blue, or glybenclamide.

A mechanistic investigation exploring the differential transfection efficiencies between the easy-to-transfect SK-BR3 and difficult-to-transfect CT26 cell lines.

BACKGROUND: Gold-polyamidoamine (AuPAMAM) has previously been shown to successfully transfect cells with high efficiency. However, we have observed that certain cell types are more amenable to Au-PAMAM transfection than others. Here we utilized two representative cell lines-a "difficult to transfect" CT26 cell line and an "easy to transfect" SK-BR3 cell line-and attempted to determine the underlying mechanism for differential transfection in both cell types. Using a commonly established poly-cationic polymer similar to PAMAM (polyethyleneimine, or PEI), we additionally sought to quantify the relative transfection efficiencies of each vector in CT26 and SK-BR3 cells, in the hopes of elucidating any mechanistic differences that may exist between the two transfection vectors. RESULTS: A comparative time course analysis of green fluorescent protein reporter-gene expression and DNA uptake was conducted to quantitatively compare PEI- and AuPAMAM-mediated transfection in CT26 and SK-BR3, while flow cytometry and confocal microscopy were used to determine the contribution of cellular uptake, endosomal escape, and cytoplasmic transport to the overall gene delivery process. Results from the time course analysis and flow cytometry studies revealed that initial complex uptake and cytoplasmic trafficking to the nucleus are likely the two main factors limiting CT26 transfectability. CONCLUSIONS: The cell type-dependent uptake and intracellular transport mechanisms impacting gene therapy remain largely unexplored and present a major hurdle in the application-specific design and efficiency of gene delivery vectors. This systematic investigation offers insights into the intracellular mechanistic processes that may account for cell-to-cell differences, as well as vector-to-vector differences, in gene transfectability.

Universal microbial diagnostics using random DNA probes.

Early identification of pathogens is essential for limiting development of therapy-resistant pathogens and mitigating infectious disease outbreaks. Most bacterial detection schemes use target-specific probes to differentiate pathogen species, creating time and cost inefficiencies in identifying newly discovered organisms. We present a novel universal microbial diagnostics (UMD) platform to screen for microbial organisms in an infectious sample, using a small number of random DNA probes that are agnostic to the target DNA sequences. Our platform leverages the theory of sparse signal recovery (compressive sensing) to identify the composition of a microbial sample that potentially contains novel or mutant species. We validated the UMD platform in vitro using five random probes to recover 11 pathogenic bacteria. We further demonstrated in silico that UMD can be generalized to screen for common human pathogens in different taxonomy levels. UMD's unorthodox sensing approach opens the door to more efficient and universal molecular diagnostics.

Changes in Optical Properties of Plasmonic Nanoparticles in Cellular Environments are Modulated by Nanoparticle PEGylation and Serum Conditions.

When plasmonic nanoparticles (NPs) are internalized by cells and agglomerate within intracellular vesicles, their optical spectra can shift and broaden as a result of plasmonic coupling of NPs in close proximity to one another. For such optical changes to be accounted for in the design of plasmonic NPs for light-based biomedical applications, quantitative design relationships between designable factors and spectral shifts need to be established. Here we begin building such a framework by investigating how functionalization of gold NPs (AuNPs) with biocompatible poly(ethylene) glycol (PEG), and the serum conditions in which the NPs are introduced to cells impact the optical changes exhibited by NPs in a cellular context. Utilizing darkfield hyperspectral imaging, we find that PEGylation decreases the spectral shifting and spectral broadening experienced by 100 nm AuNPs following uptake by Sk-Br-3 cells, but up to a 33 ± 12 nm shift in the spectral peak wavelength can still occur. The serum protein-containing biological medium also modulates the spectral changes experienced by cell-exposed NPs through the formation of a protein corona on the surface of NPs that mediates NP interactions with cells: PEGylated AuNPs exposed to cells in serum-free conditions experience greater spectral shifts than in serum-containing environments. Moreover, increased concentrations of serum (10, 25, or 50 %) result in the formation of smaller intracellular NP clusters and correspondingly reduced spectral shifts after 5 and 10 h NP-cell exposure. However, after 24 h, NP cluster size and spectral shifts are comparable and become independent of serum concentration. By elucidating the impact of PEGylation and serum concentration on the spectral changes experienced by plasmonic NPs in cells, this study provides a foundation for the optical engineering of plasmonic NPs for use in biomedical environments.

Quantifying spectral changes experienced by plasmonic nanoparticles in a cellular environment to inform biomedical nanoparticle design.

Metal nanoparticles (NPs) scatter and absorb light in precise, designable ways, making them agile candidates for a variety of biomedical applications. When NPs are introduced to a physiological environment and interact with cells, their physicochemical properties can change as proteins adsorb on their surface and they agglomerate within intracellular endosomal vesicles. Since the plasmonic properties of metal NPs are dependent on their geometry and local environment, these physicochemical changes may alter the NPs' plasmonic properties, on which applications such as plasmonic photothermal therapy and photonic gene circuits are based. Here we systematically study and quantify how metal NPs' optical spectra change upon introduction to a cellular environment in which NPs agglomerate within endosomal vesicles. Using darkfield hyperspectral imaging, we measure changes in the peak wavelength, broadening, and distribution of 100-nm spherical gold NPs' optical spectra following introduction to human breast adenocarcinoma Sk-Br-3 cells as a function of NP exposure dose and time. On a cellular level, spectra shift up to 78.6 ± 23.5 nm after 24 h of NP exposure. Importantly, spectra broaden with time, achieving a spectral width of 105.9 ± 11.7 nm at 95% of the spectrum's maximum intensity after 24 h. On an individual intracellular NP cluster (NPC) level, spectra also show significant shifting, broadening, and heterogeneity after 24 h. Cellular transmission electron microscopy (TEM) and electromagnetic simulations of NPCs support the trends in spectral changes we measured. These quantitative data can help guide the design of metal NPs introduced to cellular environments in plasmonic NP-mediated biomedical technologies.

In vivo biodistribution of nanoparticles.

Nanoparticles have potential applications in diagnostics, imaging, gene and drug delivery and other types of therapy. Iron oxide nanoparticles, gold nanoparticles and quantum dots have all generated substantial interest and their properties and applications have been thoroughly studied. Yet, metal-containing particles raise biodistribution and toxicity concerns because they can be quickly cleared from the blood by the reticuloendothelial system and can remain in organs, such as the liver and spleen, for prolonged periods of time. Design considerations, such as size, shape, surface coating and dosing, can be manipulated to prolong blood circulation and enhance treatment efficacy, but nonspecific distribution has thus far been unavoidable. Renal excretion of nanoparticles is possible and is size dependent, but the need to incorporate coatings to particles for increased circulation can hinder such excretion. Further long-term studies are needed because recent work has shown varying degrees of in vivo toxicity as well as varying levels of nanoparticle excretion over time. The interaction of these particles with immune cells and their effect on the innate and adaptive immune response also needs further characterization. Finally, more systematic in vitro approaches are needed to both guide in vivo work and better correlate nanoparticle properties to their biological effects.

Mesoscopic nanoshells: geometry-dependent plasmon resonances beyond the quasistatic limit.

The plasmon response of a spherical metallic shell becomes significantly more complex as its size is increased beyond the quasistatic limit. With increasing size and decreasing aspect ratio (r1/r2), higher order multipolar modes contribute in a more dominant manner, and two distinct core-shell geometries exist that provide the same dipole plasmon resonance, with differing relative multipolar contributions in their overall spectral response. With further increase in particle size, the geometric tunability of the core-shell structure disappears, and in the infinite radius limit the plasmon response is consistent with that of a thin metallic film.