Treatment decision for recurrences in non-small cell lung cancer during or after adjuvant osimertinib: an international Delphi consensus report.

Introduction: Osimertinib is recommended by major guidelines for use in the adjuvant setting in patients with EGFR mutation-positive NSCLC following the significant improvement in disease-free survival observed in the Phase III ADAURA trials. Due to limited real-world data in the adjuvant setting, little guidance exists on how to approach potential recurrences either during or after the completion of the treatment. This study aimed to reach a broad consensus on key treatment decision criteria in the events of recurrence. Methods: To reach a broad consensus, a modified Delphi panel study was conducted consisting of two rounds of surveys, followed by two consensus meetings and a final offline review of key statements. An international panel of experts in the field of NSCLC (n=12) was used to provide clinical insights regarding patient management at various stages of NSCLC disease including patient monitoring, diagnostics, and treatment approach for specific recurrence scenarios. This study tested recurrences occurring 1) within or outside the central nervous system (CNS), 2) during or after the adjuvant-osimertinib regimen in NSCLC disease which is 3) amenable or not amenable to local consolidative therapy. Results: Panellists agreed on various aspects of patient monitoring and diagnostics including the use of standard techniques (e.g., CT, MRI) and tumour biomarker assessment using tissue and liquid biopsies. Consensus was reached on 6 statements describing treatment considerations for the specific NSCLC recurrence scenarios. Panellists agreed on the value of osimertinib as a monotherapy or as part of the overall treatment strategy within the probed recurrence scenarios and acknowledged that more clinical evidence is required before precise recommendations for specific patient populations can be made. Discussion: This study provides a qualitative expert opinion framework for clinicians to consider within their treatment decision-making when faced with recurrence during or after adjuvant-osimertinib treatment.

The cytoprotective sequestration activity of small heat shock proteins is evolutionarily conserved.

The chaperone-mediated sequestration of misfolded proteins into inclusions is a pivotal cellular strategy to maintain proteostasis in Saccharomyces cerevisiae, executed by small heat shock proteins (sHsps) Hsp42 and Btn2. Direct homologs of Hsp42 and Btn2 are absent in other organisms, questioning whether sequestration represents a conserved proteostasis strategy and, if so, which factors are involved. We examined sHsps from Escherchia coli, Caenorhabditis elegans, and humans for their ability to complement the defects of yeast sequestrase mutants. We show that sequestration of misfolded proteins is an original and widespread activity among sHsps executed by specific family members. Sequestrase positive C. elegans' sHsps harbor specific sequence features, including a high content of aromatic and methionine residues in disordered N-terminal extensions. Those sHsps buffer limitations in Hsp70 capacity in C. elegans WT animals and are upregulated in long-lived daf-2 mutants, contributing to lifespan extension. Cellular protection by sequestration of misfolded proteins is, therefore, an evolutionarily conserved activity of the sHsp family.

Balanced activities of Hsp70 and the ubiquitin proteasome system underlie cellular protein homeostasis.

To counteract proteotoxic stress and cellular aging, protein quality control (PQC) systems rely on the refolding, degradation and sequestration of misfolded proteins. In Saccharomyces cerevisiae the Hsp70 chaperone system plays a central role in protein refolding, while degradation is predominantly executed by the ubiquitin proteasome system (UPS). The sequestrases Hsp42 and Btn2 deposit misfolded proteins in cytosolic and nuclear inclusions, thereby restricting the accessibility of misfolded proteins to Hsp70 and preventing the exhaustion of limited Hsp70 resources. Therefore, in yeast, sequestrase mutants show negative genetic interactions with double mutants lacking the Hsp70 co-chaperone Fes1 and the Hsp104 disaggregase (fes1Δ hsp104Δ, ΔΔ) and suffering from low Hsp70 capacity. Growth of ΔΔbtn2Δ mutants is highly temperature-sensitive and results in proteostasis breakdown at non-permissive temperatures. Here, we probed for the role of the ubiquitin proteasome system in maintaining protein homeostasis in ΔΔbtn2Δ cells, which are affected in two major protein quality control branches. We show that ΔΔbtn2Δ cells induce expression of diverse stress-related pathways including the ubiquitin proteasome system to counteract the proteostasis defects. Ubiquitin proteasome system dependent degradation of the stringent Hsp70 substrate firefly Luciferase in the mutant cells mirrors such compensatory activities of the protein quality control system. Surprisingly however, the enhanced ubiquitin proteasome system activity does not improve but aggravates the growth defects of ΔΔbtn2Δ cells. Reducing ubiquitin proteasome system activity in the mutant by lowering the levels of functional 26S proteasomes improved growth, increased refolding yield of the Luciferase reporter and attenuated global stress responses. Our findings indicate that an imbalance between Hsp70-dependent refolding, sequestration and ubiquitin proteasome system-mediated degradation activities strongly affects protein homeostasis of Hsp70 capacity mutants and contributes to their severe growth phenotypes.

Impact of Moderate Sedation versus Monitored Anesthesia Care on Outcomes and Cost of Endobronchial Ultrasound Transbronchial Needle Aspiration.

BACKGROUND AND OBJECTIVES: The ideal type of sedation for endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) is not known. Two previous studies comparing the diagnostic yield between moderate sedation (MS) and deep sedation/general anesthesia (DS/GA) had provided conflicting results with one study clearly favoring the latter. No study had addressed cost. This is concerning for pulmonologists without routine access to anesthesia services. Our objective was to assess the impact of MS and Monitored Anesthesia Care (sedation administered and monitored by an anesthesiologist) on the outcomes and cost of EBUS-TBNA. MATERIALS AND METHODS: We performed a retrospective review of prospectively collected data on consecutive EBUS-TBNA performed under two different types of sedation in a single academic center. A diagnostic TBNA was defined as an aspirate yielding any specific diagnosis or if subsequent surgery or follow-up of nondiagnostic/normal aspirates showed no pathology. Current Medicare time-based allowances were used for professional charges calculation. RESULTS: There was no difference observed between MS and MAC in regards of the diagnostic yield (92.9% versus 91.9%), procedure duration, number, location, and size of lymph node (LN) sampled, but there were more passes per LN with MAC. The average charges were 74.30 USD for MS and 319.91 for MAC. There were more hypotensive and desaturations episodes with MAC but none required escalation of care. CONCLUSIONS: When performed under MS, EBUS-TBNA has similar diagnostic yield as under MAC but may be associated with less side effects. The difference in sedation cost is modest; however, an additional 245$ for each EBUS done under MAC would have significant cost implications on the health system. These findings are of critical importance for bronchoscopists without routine access to anesthesia services and for optimization of healthcare cost and resource utilization.

Antibody-Negative Relapse of Goodpasture Syndrome with Pulmonary Hemorrhage.

Goodpasture syndrome is a rare autoimmune disease comprising antiglomerular basement membrane (anti-GBM) crescentic glomerulonephritis and pulmonary capillaritis with circulating anti-GBM antibodies. Rarely, antibody-negative cases have been described. We report a young, African American adult woman admitted with flank pain and hematuria with laboratory testing and kidney biopsy demonstrating anti-GBM crescentic glomerulonephritis with elevated anti-GBM antibody levels. She received treatment but remained dialysis-dependent. She was seronegative and clinically stable until she presented 8 months later with dyspnea and hemoptysis requiring mechanical ventilation. Bronchoscopy revealed diffuse alveolar hemorrhage. She was treated for relapse of Goodpasture syndrome. However, anti-GBM antibodies were undetectable. This case emphasizes prompt diagnosis and treatment of Goodpasture syndrome to preserve renal function. Additionally, clinical manifestations of Goodpasture syndrome and its degree of activity do not necessarily correlate with the actual antibody titer on relapse. Clinicians should have enhanced awareness of this atypical presentation of a rare disease.

Exploring the mechanism of fluorescence quenching in proteins induced by tetracycline.

The binding of the antibiotic tetracycline hydrochloride (TC) to three proteins was investigated by steady-state, time-resolved, and circular dichroism spectroscopy. The tryptophan (Trp) amino acid residues were used as an intrinsic fluorophore to decipher the structure-function relationship. As monitored by CD spectroscopy, the addition of TC causes the protein to alter some of its helical content although such changes are only marginal. The gradual decrease in fluorescence intensity of Trp can be ascribed to static quenching which takes place by the interaction of the drug with the protein. Besides Trp quenching, there is evidence of fluorescence resonance energy transfer (FRET) in all three proteins with different values of efficiency of energy transfer. Various quenching/binding and thermodynamic parameters associated with such drug-protein interactions have been estimated. The results thus obtained can provide guidelines to synthetic chemists to design and synthesize target-oriented drugs.