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Bronchial thermoplasty: implementing best practice in the era of cost containment.
Increasing dependence on advanced technologies in the 21st century has created a dilemma between the practice and business of medicine. From information technology to robotic surgery, new technologies have expanded treatment possibilities and have potentially improved patient outcomes and safety. Simultaneously, their escalating costs limit access for certain patients and health care facilities. Nevertheless, medical decisions should not simply be based on cost. Input from physicians and other health care specialists as well as adherence to best practice position statements, are vital to implementing truly cost-effective strategies in medicine. Bronchial thermoplasty (BT), a US Food and Drug Administration approved bronchoscopy procedure in difficult-to-control persistent asthma, is a prime example of a new technology facing cost and implementation challenges. We discuss the specific indications and contraindications for BT and review recent real-world experiences that can provide the foundation for building a comprehensive asthma program that provides BT for difficult-to-control asthma patients who fail national guideline treatment recommendations after an adequate clinical trial of one. We also offer insight into the barriers to implementing a successful BT program and strategies for overcoming them
Regret Bounds and Experimental Design for Estimate-then-Optimize
In practical applications, data is used to make decisions in two steps:
estimation and optimization. First, a machine learning model estimates
parameters for a structural model relating decisions to outcomes. Second, a
decision is chosen to optimize the structural model's predicted outcome as if
its parameters were correctly estimated. Due to its flexibility and simple
implementation, this ``estimate-then-optimize'' approach is often used for
data-driven decision-making. Errors in the estimation step can lead
estimate-then-optimize to sub-optimal decisions that result in regret, i.e., a
difference in value between the decision made and the best decision available
with knowledge of the structural model's parameters. We provide a novel bound
on this regret for smooth and unconstrained optimization problems. Using this
bound, in settings where estimated parameters are linear transformations of
sub-Gaussian random vectors, we provide a general procedure for experimental
design to minimize the regret resulting from estimate-then-optimize. We
demonstrate our approach on simple examples and a pandemic control application
Accelerated Alternating Descent Methods for Dykstra-like problems
International audienceThis paper extends recent results by the first author and T. Pock (ICG, TU Graz, Austria) on the acceleration of alternating minimization techniques for quadratic plus nonsmooth objectives depending on two variables. We discuss here the strongly convex situation, and how ‘fast’ methods can be derived by adapting the overrelaxation strategy of Nesterov for projected gradient descent. We also investigate slightly more general alternating descent methods, where several descent steps in each variable are alternatively performed
Penning traps with unitary architecture for storage of highly charged ions
Penning traps are made extremely compact by embedding rare-earth permanent
magnets in the electrode structure. Axially-oriented NdFeB magnets are used in
unitary architectures that couple the electric and magnetic components into an
integrated structure. We have constructed a two- magnet Penning trap with
radial access to enable the use of laser or atomic beams, as well as the
collection of light. An experimental apparatus equipped with ion optics is
installed at the NIST electron beam ion trap (EBIT) facility, constrained to
fit within 1 meter at the end of a horizontal beamline for transporting highly
charged ions. Highly charged ions of neon and argon, extracted with initial
energies up to 4000 eV per unit charge, are captured and stored to study the
confinement properties of a one-magnet trap and a two-magnet trap. Design
considerations and some test results are discussed
Post-radiation sarcoma of the neck treated with re-irradiation followed by wide excision
BACKGROUND: Post-radiation sarcoma (PRS) is an uncommon disease manifesting as sarcoma in a previously irradiated field, usually with a latent period of 5 years or more. Literature is limited to small series. Optimal management of this disease is unclear. Positive margins are common following attempted curative surgery and outcomes are poor. Radiotherapy is hardly used and its effect on PRS is not known. We described a case of PRS treated with preoperative radiotherapy followed by margin-negative wide excision. CASE PRESENTATION: The 59-year-old patient presented with a mass in the left supraclavicular fossa and numbness in the arm, six years following radical irradiation of the head and neck for nasopharyngeal carcinoma. Open biopsy showed pleomorphic spindle cell sarcoma. She was treated with pre-operative hyperfractionated radiotherapy followed by margin-negative wide excision and nerve grafting. Cumulative radiation dose to the supraclavicular fossa was 98 Gy. Histological examination of the post-irradiation tumor specimens showed evidence of significant tumor response to re-irradiation. The patient remained free of disease five years after surgery with excellent functional outcome. CONCLUSION: Role of radiotherapy in PRS is uncertain. We described a case that was successfully managed with preoperative radiotherapy and margin-negative wide excision in terms of tumor control and functional outcomes. The impact of radiotherapy was demonstrated in the post-irradiation resected specimen. Further investigation using re-irradiation and surgery in PRS is warranted
Appropriately differentiated ARPE-19 cells regain phenotype and gene expression profiles similar to those of native RPE cells.
PurposeThe RPE cell line ARPE-19 provides a dependable and widely used alternative to native RPE. However, replication of the native RPE phenotype becomes more difficult because these cells lose their specialized phenotype after multiple passages. Compounding this problem is the widespread use of ARPE-19 cells in an undifferentiated state to attempt to model RPE functions. We wished to determine whether suitable culture conditions and differentiation could restore the RPE-appropriate expression of genes and proteins to ARPE-19, along with a functional and morphological phenotype resembling native RPE. We compared the transcriptome of ARPE-19 cells kept in long-term culture with those of primary and other human RPE cells to assess the former's inherent plasticity relative to the latter.MethodsARPE-19 cells at passages 9 to 12 grown in DMEM containing high glucose and pyruvate with 1% fetal bovine serum were differentiated for up to 4 months. Immunocytochemistry was performed on ARPE-19 cells grown on filters. Total RNA extracted from ARPE-19 cells cultured for either 4 days or 4 months was used for RNA sequencing (RNA-Seq) analysis using a 2 × 50 bp paired end protocol. The RNA-Seq data were analyzed to identify the affected pathways and recognize shared ontological classification among differentially expressed genes. RPE-specific mRNAs and miRNAs were assessed with quantitative real-time (RT)-PCR, and proteins with western blotting.ResultsARPE-19 cells grown for 4 months developed the classic native RPE phenotype with heavy pigmentation. RPE-expressed genes, including RPE65, RDH5, and RDH10, as well as miR-204/211, were greatly increased in the ARPE-19 cells maintained at confluence for 4 months. The RNA-Seq analysis provided a comprehensive view of the relative abundance and differential expression of the genes in the differentiated ARPE-19 cells. Of the 16,757 genes with detectable signals, nearly 1,681 genes were upregulated, and 1,629 genes were downregulated with a fold change of 2.5 or more differences between 4 months and 4 days of culture. Gene Ontology analysis showed that the upregulated genes were associated with visual cycle, phagocytosis, pigment synthesis, cell differentiation, and RPE-related transcription factors. The majority of the downregulated genes play a role in cell cycle and proliferation.ConclusionsThe ARPE-19 cells cultured for 4 months developed a phenotype characteristic of native RPE and expressed proteins, mRNAs, and miRNAs characteristic of the RPE. Comparison of the ARPE-19 RNA-Seq data set with that of primary human fetal RPE, embryonic stem cell-derived RPE, and native RPE revealed an important overall similar expression ratio among all the models and native tissue. However, none of the cultured models reached the absolute values in the native tissue. The results of this study demonstrate that low-passage ARPE-19 cells can express genes specific to native human RPE cells when appropriately cultured and differentiated
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