The BCKDH kinase inhibitor BT2 promotes BCAA disposal and mitochondrial proton leak in both insulin-sensitive and insulin-resistant C2C12 myotubes.

Elevated circulating branched-chain amino acids (BCAAs) have been correlated with the severity of insulin resistance, leading to recent investigations that stimulate BCAA metabolism for the potential benefit of metabolic diseases. BT2 (3,6-dichlorobenzo[b]thiophene-2-carboxylic acid), an inhibitor of branched-chain ketoacid dehydrogenase kinase, promotes BCAA metabolism by enhancing BCKDH complex activity. The purpose of this report was to investigate the effects of BT2 on mitochondrial and glycolytic metabolism, insulin sensitivity, and de novo lipogenesis both with and without insulin resistance. C2C12 myotubes were treated with or without low or moderate levels of BT2 with or without insulin resistance. Western blot and quantitative real-time polymerase chain reaction were used to assess protein and gene expression, respectively. Mitochondrial, nuclei, and lipid content were measured using fluorescent staining and microscopy. Cell metabolism was assessed via oxygen consumption and extracellular acidification rate. Liquid chromatography-mass spectrometry was used to quantify BCAA media content. BT2 treatment consistently promoted mitochondrial uncoupling following 24-h treatment, which occurred largely independent of changes in expressional profiles associated with mitochondrial biogenesis, mitochondrial dynamics, BCAA catabolism, insulin sensitivity, or lipogenesis. Acute metabolic studies revealed a significant and dose-dependent effect of BT2 on mitochondrial proton leak, suggesting BT2 functions as a small-molecule uncoupler. Additionally, BT2 treatment consistently and dose-dependently reduced extracellular BCAA levels without altering expression of BCAA catabolic enzymes or pBCKDHa activation. BT2 appears to act as a small-molecule mitochondrial uncoupler that promotes BCAA utilization, though the interplay between these two observations requires further investigation.

The effect of insulin resistance on extracellular BCAA accumulation and SLC25A44 expression in a myotube model of skeletal muscle insulin resistance.

Insulin resistance is often accompanied by elevated circulating branched-chain amino acids (BCAA). We investigated the effects of insulin resistance on the mitochondrial BCAA transporter, SLC25A44, using a myotube model of insulin resistance. Insulin sensitivity and SLC25A44 expression were assessed via Western blot. Liquid chromatography-mass spectrometry was used to evaluate extracellular BCAA media content. Insulin resistance reduced pAkt activation following insulin stimulation but did not alter SLC25A44 expression. Under select conditions, insulin resistance led to the accumulation of extracellular BCAA.

Effect of AMPK activation and glucose availability on myotube LAT1 expression and BCAA utilization.

Those with insulin resistance often display increased circulating branched-chain amino acids (BCAA), which has been largely attributable to reduced BCAA catabolic capacity. Metabolic stimuli such as exercise activates AMP-activated kinase (AMPK), which promotes the metabolism of BCAA and induction/activation of BCAA catabolic enzymes. Though much attention has been paid to BCAA catabolic machinery, few studies have assessed the effect of AMPK activation on the predominant BCAA transporter, L-type amino acid transporter 1 (LAT1). This study assessed the effect of AMPK activation on LAT1 expression via common chemical AMPK activators in a cell model of skeletal muscle. C2C12 myotubes were treated with either 1 mM AICAR, 1 mM Metformin, or filter-sterilized water (control) for 24 h with either low- (5 mM) or high-glucose (25 mM) media. LAT1 and pAMPK protein content were measured via western blot. BCAA media content was measured using liquid chromatography-mass spectrometry. AICAR treatment significantly increased pAMPK and reduced LAT1 expression. Collectively, pAMPK and LAT1 displayed a significant inverse relationship independent of glucose levels. During low-glucose experiments, AICAR-treated cells had higher BCAA media content compared to other groups, and an inverse relationship between LAT1 and BCAA media content was observed, however, these effects were not consistently observed during high-glucose conditions. Further investigation with AICAR with and without concurrent LAT1 inhibition (via JPH203) also revealed reduced BCAA utilization in AICAR-treated cells regardless of LAT1 inhibition (which also independently reduced BCAA utilization). pAMPK activation via AICAR (but not Metformin) may reduce LAT1 expression and BCAA uptake in a glucose-dependent manner.

5-Aza-2'-deoxycytidine-mediated DNA hypomethylation with and without concurrent insulin resistance suppresses myotube mitochondrial capacity.

Type 2 diabetes is characterized by elevated blood glucose and reduced insulin sensitivity in target tissues. Moreover, reduced mitochondrial metabolism and expressional profile of genes governing mitochondrial metabolism (such as peroxisome proliferator-activated receptor gamma coactivator 1-alpha [PGC-1α]) are also reduced during insulin resistance. Epigenetic regulation via DNA methylation of genes including PGC-1α may contribute to diminished mitochondrial capacity, while hypomethylation of PGC-1α (such as that invoked by exercise) has been associated with increased PGC-1α expression and favorable metabolic outcomes. The purpose of the present report is to characterize the effects of DNA hypomethylation on myotube metabolism and expression of several related metabolic targets. C2C12 myotubes were treated with 5-Aza-2'-deoxycytidine (5-Aza) for either 24 or 72 h both with and without hyperinsulinemic-induced insulin resistance. Mitochondrial and glycolytic metabolism were measured via oxygen consumption and extracellular acidification rate, respectively. Metabolic gene and protein expression were assessed via quantitative real time polymerase chain reaction and western blot analysis, respectively. Though expression of PGC-1α and other related targets remained unaltered, insulin resistance and 5-Aza treatment significantly reduced mitochondrial metabolism. Similarly, peak glycolytic metabolism was diminished by 5-Aza-treated cells, while basal glycolytic metabolism was unaltered. 5-Aza also reduced the expression of branched-chain amino acid (BCAA) catabolic components, however BCAA utilization was enhanced during insulin resistance with 5-Aza treatment. Together the present work provides proof-of-concept evidence of the potential role of DNA methylation in the regulation of mitochondrial metabolism and the potential interactions with insulin resistance in a model of skeletal muscle.

Branched-chain amino acids at supraphysiological but not physiological levels reduce myotube insulin sensitivity.

AIMS: Branched-chain amino acids (BCAA) are often emphasized in the diets of avid exercisers, yet population data demonstrates a correlation between circulating BCAA and insulin resistance. However, it is unclear if BCAA independently promote insulin resistance in otherwise healthy cells. The purpose of this study is to examine the effect of a BCAA mixture on muscle insulin signaling in vitro in both insulin resistant and sensitive cells. MATERIALS AND METHODS: C2C12 myotubes were treated with a BCAA mixture containing leucine:isoleucine:valine at a ratio of 2:1:1 at 0.2, 2, or 20 mM (based on leucine content) for either 30 min, 1 day, or 6 days. Western blot was used to assess insulin sensitivity of cells treated with BCAA both with and without concurrent insulin resistance, and, with and without insulin stimulation. RESULTS: BCAA treatment for 1 day significantly reduced basal, but not insulin-stimulated pAkt expression. BCAA treatment for 6 days resulted in significantly reduced basal insulin signaling in healthy cells and insulin-stimulated insulin signaling in insulin resistant (but not insulin sensitive) cells. CONCLUSION: Similar to previous observations demonstrating BCAA may correlate with insulin resistance during metabolically stressed conditions, we demonstrate excessively high BCAA exposure can negatively influence basal insulin signaling, as well as insulin sensitivity in insulin resistant myotubes. However, given the intentionally high concentrations of BCAA used in this study, the extent to which these observations translate to in vivo models is unclear and warrants further investigation.

Excess glutamine does not alter myotube metabolism or insulin sensitivity.

Glutamine is an amino acid previously linked with improved skeletal muscle metabolism and insulin signaling, however, past observations often use cell culture models with only supraphysiological concentrations. Additionally, past reports have yet to simultaneously investigate both metabolic outcomes and insulin signaling. The present report utilized cell culture experiments and measured the effects of both physiological and supraphysiological levels of glutamine on myotube metabolism and insulin signaling/resistance. It was hypothesized the addition of glutamine at any level would increase cell metabolism and related gene expression, as well as improve insulin signaling versus respective control cells. C2C12 myotubes were treated with glutamine ranging from 0.25 mM-4 mM (or media control) for 24 h to capture a range of physiological and supraphysiological concentrations. qRT-PCR was used to measure metabolic gene expression. Mitochondrial and glycolytic metabolism were measured via oxygen consumption and extracellular acidification rate, respectively. Insulin sensitivity (indicated by pAkt:Akt) and metabolism following glucose/insulin infusion were also assessed. Glutamine treatment consistently increased mitochondrial and glycolytic metabolism versus true controls (cells treated with media void of glutamine), however, supraphysiological glutamine did not enhance metabolism beyond that of cells with physiological levels of glutamine. Neither physiological nor supraphysiological levels of glutamine altered insulin signaling regardless of insulin stimulation or insulin resistance when compared with respective controls. These data demonstrate excess glutamine does not appear to alter myotube metabolism or glucose disposal when base levels of glutamine are present. Moreover, glutamine does not appear to alter insulin sensitivity regardless of level of insulin resistance or presence of insulin stimulation.

Acute introduction of phosphoserine-129 α-synuclein induces severe swelling of mitochondria at lamprey synapses.

Abnormal synaptic aggregation of α-synuclein is linked to cognitive deficits in Parkinson's disease (PD). While the impacts of excess α-synuclein on synaptic function are well established, comparatively less is known about the effects on local mitochondria. Here, we examined morphological features of synaptic mitochondria treated with wild type (WT) or phosphoserine 129 (pS129) α-synuclein, a variant with prominent synaptic accumulation in PD. Acute introduction of pS129 α-synuclein to lamprey synapses caused an activity-dependent swelling and bursting of mitochondria, which did not occur with WT α-synuclein. These pS129-induced effects on mitochondria likely contribute to the synaptic deficits observed in PD.

Physiological 4-phenylbutyrate promotes mitochondrial biogenesis and metabolism in C2C12 myotubes.

Type 2 diabetes is characterized by elevated circulating blood metabolites such as glucose, insulin, and branched chain amino acids (BCAA), which often coincide with reduced mitochondrial function. 4-Phenylbutyrate (PBA), an ammonia scavenger, has been shown to activate BCAA metabolism, resolve endoplasmic reticulum (ER) stress, and rescue BCAA-mediated insulin resistance. To determine the effect of PBA on the altered metabolic phenotype featured in type 2 diabetes, the present study investigated the effect of PBA on various metabolic parameters including mitochondrial metabolism and mitochondrial biogenesis. C2C12 myotubes were treated with PBA at 0.5 mM (representing physiologically attainable blood concentrations) or 10 mM (representing physiologically unattainable/proof-of-concept levels) for up to 24 h. Mitochondrial and glycolytic metabolism were assessed via oxygen consumption and extracellular acidification rate, respectively. Mitochondrial content, lipid content, and ER stress were measured by fluorescent staining. Metabolic gene expression was measured by qRT-PCR. Both doses of PBA increased expression of indicators of mitochondrial biogenesis, though only PBA at 0.5 mM increased mitochondrial function and content while 10 mM PBA reduced mitochondrial function and content. PBA at 0.5 mM also rescued reduced mitochondrial function during insulin resistance, though PBA also caused a reduced insulin stimulated pAkt expression during insulin resistance. PBA treatment also increased extracellular BCAA accumulation during insulin resistance despite unchanged pBCKDH expression. Taken together, PBA may increase mitochondrial biogenesis, content, and function in a dose-dependent fashion which may have implications for prevention or treatment of metabolic disease such as insulin resistance.

Insulin resistance promotes extracellular BCAA accumulation without altering LAT1 content, independent of prior BCAA treatment in a myotube model of skeletal muscle.

PURPOSE: Type 2 diabetes is characterized by reduced insulin sensitivity which correlates with increased circulating BCAA. These experiments investigated the effects of insulin resistance with and without excess BCAA on myotube insulin sensitivity and L-type amino acid transporter-1 (LAT1). METHODS: C2C12 myotubes were treated with or without excess BCAA for 1 or 6 days, both with and without insulin resistance. Western blot was used to assess insulin sensitivity and LAT1 content. Liquid chromatography-mass spectrometry was used to evaluate BCAA media content. RESULTS: Insulin resistance was associated with significantly increased extracellular BCAA accumulation independent of LAT1 content. Conversely, prior BCAA treatment was not associated with extracellular BCAA accumulation regardless of level of insulin sensitivity. CONCLUSION: These data suggest insulin resistance, but not BCAA treatment, promotes extracellular BCAA accumulation independent of changes in LAT1 content, implicating insulin resistance as a causal agent of extracellular BCAA accumulation.

PPARß/δ Agonism with GW501516 Increases Myotube PGC-1α Content and Reduces BCAA Media Content Independent of Changes in BCAA Catabolic Enzyme Expression.

Background: Type 2 diabetes is characterized by reduced insulin sensitivity, elevated blood metabolites, and reduced mitochondrial metabolism with reduced expression of genes governing metabolism such as peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). PGC-1α regulates the expression of branched-chain amino acid (BCAA) metabolism, and thus, increased circulating BCAA in diabetics may be partially explained by reduced PGC-1α expression. PGC-1α functions in-part through interactions with peroxisome proliferator-activated receptor ß/δ (PPARß/δ). The present report examined the effects of the PPARß/δ agonism on cell metabolism and related gene/protein expression of cultured myotubes, with a primary emphasis on determining the effects of GW on BCAA disposal and catabolic enzyme expression. Methods: C2C12 myotubes were treated with GW501516 (GW) for up to 24 hours. Mitochondrial and glycolytic metabolism were measured via oxygen consumption and extracellular acidification rate, respectively. Metabolic gene and protein expression were assessed via quantitative real-time polymerase chain reaction (qRT-PCR) and western blot, respectively. Media BCAA content was assessed via liquid chromatography-mass spectrometry (LC/MS). Results: GW significantly increased PGC-1α protein expression, mitochondrial content, and mitochondrial function. GW also significantly reduced BCAA content within culture media following 24-hour treatment; however, expression of BCAA catabolic enzymes/transporter was unchanged. Conclusion: These data confirm the ability of GW to increase muscle PGC-1α content and decrease BCAA media content without affecting BCAA catabolic enzymes/transporter. These findings suggest heightened BCAA uptake (and possibly metabolism) may occur without substantial changes in the protein levels of related cell machinery.

The Selective LAT1 Inhibitor JPH203 Enhances Mitochondrial Metabolism and Content in Insulin-Sensitive and Insulin-Resistant C2C12 Myotubes.

Population data have shown an association between higher circulating branched-chain amino acids (BCAA) and the severity of insulin resistance in people with diabetes. While several studies have assessed BCAA metabolism as a potential target for regulation, less attention has been paid to the role of L-type amino acid transporter 1 (LAT1), the primary transporter of BCAA in skeletal muscle. The aim of this study was to assess the impact of JPH203 (JPH), a LAT1 inhibitor, on myotube metabolism in both insulin-sensitive and insulin-resistant myotubes. C2C12 myotubes were treated with or without 1 µM or 2 µM JPH for 24 h with or without insulin resistance. Western blot and qRT-PCR were used to assess protein content and gene expression, respectively. Mitochondrial and glycolytic metabolism were measured via Seahorse Assay, and fluorescent staining was used to measure mitochondrial content. BCAA media content was quantified using liquid chromatography-mass spectrometry. JPH at 1 µM (but not 2 µM) increased mitochondrial metabolism and content without inducing changes in mRNA expression of transcripts associated with mitochondrial biogenesis or mitochondrial dynamics. Along with increased mitochondrial function, 1µM treatment also reduced extracellular leucine and valine. JPH at 2 µM reduced pAkt signaling and increased extracellular accumulation of isoleucine without inducing changes in BCAA metabolic genes. Collectively, JPH may increase mitochondrial function independent of the mitochondrial biogenic transcription pathway; however, high doses may reduce insulin signaling.

Using the internet to trace contacts of a fatal meningococcemia case-New York City, 2010.

In August 2010, the New York City Department of Health and Mental Hygiene (DOHMH) conducted an investigation to identify and provide antibiotic prophylaxis to close contacts of a patient who had died of invasive meningococcal disease. Traditional contact tracing, which relies on interviews with the patient's close associates, identified 3 persons meeting prophylaxis criteria. In addition, DOHMH learned of an Internet site used by the patient to arrange anonymous sexual encounters. By working with the Internet site administrator through a liaison, DOHMH sent notification to 15 additional persons potentially at risk for meningococcal disease; of those, at least 1 met prophylaxis criteria. The Internet has been used previously for partner notification by sexually transmitted disease control programs. This case report illustrates how the Internet can aid contact investigations for other communicable diseases, especially when identifying potential contacts is urgent, patients have died, or contacts are unknown to the patient's associates.

AICAR stimulates mitochondrial biogenesis and BCAA catabolic enzyme expression in C2C12 myotubes.

Type 2 diabetes is characterized by reduced insulin sensitivity, elevated blood metabolites, and reduced mitochondrial metabolism. Insulin resistant populations often exhibit reduced expression of genes governing mitochondrial metabolism such as peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). Interestingly, PGC-1α regulates the expression of branched-chain amino acid (BCAA) metabolism, and thus, the consistently observed increased circulating levels of BCAA in diabetics may be partially explained by reduced PGC-1α expression. Conversely, PGC-1α upregulation appears to increase BCAA catabolism. PGC-1α activity is regulated by 5'-AMP-activated protein kinase (AMPK), however, only limited experimental data exists on the effect of AMPK activation in the regulation of BCAA catabolism. The present report examined the effects of the commonly used AMPK activator 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) on the metabolism and expression of several related targets (including BCAA catabolic enzymes) of cultured myotubes. C2C12 myotubes were treated with AICAR at 1 mM for up to 24 h. Mitochondrial and glycolytic metabolism were measured via oxygen consumption and extracellular acidification rate, respectively. Metabolic gene and protein expression were assessed via qRT-PCR and western blot, respectively. AICAR treatment significantly increased mitochondrial content and peak mitochondrial capacity. AICAR treatment also increased AMPK activation and mRNA expression of several regulators of mitochondrial biogenesis but reduced glycolytic metabolism and mRNA expression of several glycolytic enzymes. Interestingly, branched-chain alpha-keto acid dehydrogenase a (BCKDHa) protein was significantly increased following AICAR-treatment suggesting increased overall BCAA catabolic capacity in AICAR-treated cells. Together, these experiments demonstrate AICAR/AMPK activation can upregulate BCAA catabolic machinery in a model of skeletal muscle.

Excess branched-chain amino acids alter myotube metabolism and substrate preference which is worsened by concurrent insulin resistance.

PURPOSE: Branched-chain amino acids (BCAA) have been shown to enhance several cellular signaling pathways including protein synthesis and mitochondrial biogenesis, yet population data demonstrate a correlation between circulating BCAA and severity of insulin resistance which has been hypothesized to be, in part, a byproduct of BCAA inhibition of mitochondrial function. The purpose of this study is to examine the effect of a BCAA mixture on muscle metabolism and related gene expression in vitro. METHODS: C2C12 myotubes were treated with a BCAA mixture containing leucine:isoleucine:valine at a ratio of 2:1:1 at 0.2, 2, or 20 mM (based on leucine content) for 6 days. qRT-PCR was used to measure metabolic gene expression. Oxygen consumption and extracellular acidification were used to assess mitochondrial and glycolytic metabolism, respectively. Mitochondrial content was determined via mitochondrial-specific staining. RESULTS: Despite significantly elevated mitochondrial staining, 6-day BCAA treatment reduced basal mitochondrial metabolism at a supraphysiological concentration (20 mM) in both insulin sensitive and resistant cells. Peak mitochondrial capacity was also reduced in insulin-resistant (but not insulin sensitive) cells. Conversely, basal glycolytic metabolism was elevated following 20 mM BCAA treatment, regardless of insulin resistance. In addition, insulin-resistant cells treated with 20 mM BCAA exhibited reduced gene expression of Ppargc1a, Cytc, Atp5b, Glut4, and several glycolytic enzymes versus insulin sensitive cells treated with 20 mM BCAA. CONCLUSIONS: Collectively, these findings suggest BCAA at supraphysiologically high levels may negatively alter mitochondrial metabolism, and concurrent insulin resistance may also diminish peak mitochondrial capacity, as well as impede molecular adaptations that support a transition to a glycolytic preference/compensation.

Branched-Chain Amino Acids and Mitochondrial Biogenesis: An Overview and Mechanistic Summary.

Branched-chain amino acids (BCAA) are essential in the diet and promote several vital cell responses which may have benefits for health and athletic performance, as well as disease prevention. While BCAA are well-known for their ability to stimulate muscle protein synthesis, their effects on cell energetics are also becoming well-documented, but these receive less attention. In this review, much of the current evidence demonstrating BCAA ability (as individual amino acids or as part of dietary mixtures) to alter regulators of cellular energetics with an emphasis on mitochondrial biogenesis and related signaling is highlighted. Several studies have shown, both in vitro and in vivo, that BCAA (either individual or as a mixture) may promote signaling associated with increased mitochondrial biogenesis including the upregulation of master regulator of mitochondrial biogenesis peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), as well as numerous downstream targets and related function. However, sparse data in humans and the difficulty of controlling variables associated with feeding studies leave the physiological relevance of these findings unclear. Future well-controlled diet studies will be needed to assess if BCAA consumption is associated with increased mitochondrial biogenesis and improved metabolic outcomes in healthy and/or diseased human populations.

Reporting of patient safety incidents in minimally invasive thoracic surgery: a national registered thoracic surgeons experience for improvement of patient safety.

OBJECTIVES: The reporting of patient safety incidents (PSIs) occurring in minimally invasive thoracic surgery (MITS) is crucial. However, previous reports focused mainly on catastrophic events whereas minor events are often underreported. METHODS: All voluntary reports of MITS-related PSIs were retrospectively extracted from the French REX database for 'in-depth analysis'. From 2008 to 2019, we retrospectively analysed and graded events according to the WHO classification of PSIs: near miss events, no harm incidents and harmful incidents. Causes and corrective measures were analysed according to the human-technology-organization triad. RESULTS: Of the 5145 cardiothoracic surgery PSIs declared, 407 were related to MITS. Among them, MITS was performed for primary lung cancer in 317 (78%) and consisted in a lobectomy in 249 (61%) patients. PSIs were: near miss events in 42 (10%) patients, no harm incidents in 81 (20%) patients and harmful incidents in 284 (70%) patients (mild: n = 163, 40%; moderate: n = 78, 19%; severe: n = 36, 9%; and deaths: n = 7, 2%). Human factors represented the most important cause of PSIs with 267/407 (65.6%) cases, including mainly vascular injuries (n = 90; 22%) and non-vascular injuries (n = 43; 11%). Pulmonary arteries were the most affected site with 57/91 cases (62%). In all, there were 7 deaths (2%), 53 patients required second surgery (13%) and 30 required additional lung resection (7%). CONCLUSIONS: The majority of reported MITS -related PSIs were non-catastrophic. Human factors were the main cause of PSIs. Systematic reporting and analysis of these PSIs will allow surgeon and his team to avoid a large proportion of them.

Prevalence of Complementary/Alternative Medicine use in Cancer Patients in a Tertiary Hospital in Puerto Rico.

OBJECTIVE: We conducted a study in a tertiary hospital to investigate complementary and alternative medicine (CAM) prevalence in a Puerto Rican population. The study also evaluated demographic and clinical factors in order to correlate them with CAM use. METHODS: Spanish speaking residents with a known diagnosis of cancer being followed in the outpatient facilities at Auxilio Mutuo Cancer Center were invited to participate in the study. Patients who read and signed a consent form were given a questionnaire inquiring, among various things, on their use of any CAM treatment, education level, gender, place of residence and whether they had consulted their oncologist. The questionnaire also asked about their expectations for use of CAM. RESULTS: 215 patients were approached to participate out of which 200 signed the consent and accepted to participate. A total of 95 of 200 patients (47.5%) mentioned that they utilized at least one CAM treatment. Six factors were then analyzed for their correlation with CAM usage and three yielded statistically significant results at p<.05: age group, education level, and area of residence. After multivariate analysis all of these three factors behaved as independent variables. Gender, tumor type and stage were not significantly associated with use of CAM. CONCLUSION: Our data show that CAM use is significantly more common in those with higher education, younger age, and those living in non-metropolitan areas. Vitamin C and soursop (Graviola or guanábana) proved to be the two most common CAM treatments, respectively.

Validation and update of the thoracic surgery scoring system (Thoracoscore) risk model.

OBJECTIVES: The performance of prediction models tends to deteriorate over time. The purpose of this study was to update the Thoracoscore risk prediction model with recent data from the Epithor nationwide thoracic surgery database. METHODS: From January 2016 to December 2017, a total of 56 279 patients were operated on for mediastinal, pleural, chest wall or lung disease. We used 3 recommended methods to update the Thoracoscore prediction model and then proceeded to develop a new risk model. Thirty-day hospital mortality included patients who died within the first 30 days of the operation and those who died later during the same hospital stay. RESULTS: We compared the baseline patient characteristics in the original data used to develop the Thoracoscore prediction model and the validation data. The age distribution was different, with specifically more patients older than 65 years in the validation group. Video-assisted thoracoscopy accounted for 47% of surgeries in the validation group compared but only 18% in the original data. The calibration curve used to update the Thoracoscore confirmed the overfitting of the 3 methods. The Hosmer-Lemeshow goodness-of-fit test was significant for the 3 updated models. Some coefficients were overfitted (American Society of Anesthesiologists score, performance status and procedure class) in the validation data. The new risk model has a correct calibration as indicated by the Hosmer-Lemeshow goodness-of-fit test, which was non-significant. The C-index was strong for the new risk model (0.84), confirming the ability of the new risk model to differentiate patients with and without the outcome. Internal validation shows no overfitting for the new model. CONCLUSIONS: The new Thoracoscore risk model has improved performance and good calibration, making it appropriate for use in current clinical practice.

A New Salvage Regimen for Aggressive Lymphomas Based on Gemcitabine, Rituximab, and Oxaliplatin Followed by Lenalidomide (GROC-Rev).

PURPOSE: To evaluate the impact of lenalidomide in patients with aggressive lymphoma who experienced less than complete response (CR) or as maintenance therapy after CR after gemcitabine, rituximab, and oxaliplatin salvage chemotherapy (GROC-Rev regimen). PATIENTS AND METHODS: Patients with relapsed/refractory non-Hodgkin lymphoma received up to 6 GROC-Rev courses: rituximab (375 mg/m2 provided intravenously) on day 1, oxaliplatin (100 mg/m2 provided intravenously; 2 hours), gemcitabine (provided 1250 mg/m2 intravenously; 30 minutes) on day 2, and pegfilgrastim (6 mg provided subcutaneously) on day 3. Patients switched to lenalidomide if they did not experience at least partial response (PR) after their second GROC-Rev course, or if they experienced less than a CR after 6 courses. RESULTS: In 33 patients, overall response was 61% (CR = 39%). Of 17 patients with PR who continued to 6 courses, 10 (59%) experienced CR and 7 PR as maximum response; of these 7, 1 died before receiving lenalidomide, 1 experienced CR while receiving lenalidomide (17%), and 2 experienced a further PR (33%). Of 16 with disease that failed to respond to GROC-Rev after their second course, 2 died before lenalidomide could be administered, and 2 experienced CR (14%) and 1 PR (7%) after lenalidomide. Overall survival and progression-free survival were 47% and 33% at 2 years. Grade 3/4 adverse events included neutropenia, thrombocytopenia, and/or anemia (n = 5), neutropenic infection (n = 3), urinary tract infection (n = 3), pneumonia (n = 2), cellulitis (n = 2), and seizure (n = 1). Eight went on to receive transplants. CONCLUSION: GROC-Rev is an effective and well-tolerated salvage regimen consisting of chemotherapy followed by lenalidomide maintenance in patients with relapsed/refractory non-Hodgkin lymphoma. Simultaneous administration of these agents is worth exploring in future studies.

Comparison of Epithor clinical national database and medico-administrative database to identify the influence of case-mix on the estimation of hospital outliers.

BACKGROUND: The national Epithor database was initiated in 2003 in France. Fifteen years on, a quality assessment of the recorded data seemed necessary. This study examines the completeness of the data recorded in Epithor through a comparison with the French PMSI database, which is the national medico-administrative reference database. The aim of this study was to demonstrate the influence of data quality with respect to identifying 30-day mortality hospital outliers. METHODS: We used each hospital's individual FINESS code to compare the number of pulmonary resections and deaths recorded in Epithor to the figures found in the PMSI. Centers were classified into either the good-quality data (GQD) group or the low-quality data (LQD) group. To demonstrate the influence of case-mix quality on the ranking of centers with low-quality data, we used 2 methods to estimate the standardized mortality rate (SMR). For the first (SMR1), the expected number of deaths per hospital was estimated with risk-adjustment models fitted with low-quality data. For the second (SMR2), the expected number of deaths per hospital was estimated with a linear predictor for the LQD group using the coefficients of a logistic regression model developed from the GQD group. RESULTS: Of the hospitals that use Epithor, 25 were classified in the GQD group and 75 in the LQD group. The 30-day mortality rate was 2.8% (n = 300) in the GQD group vs. 1.9% (n = 181) in the LQD group (P <0.0001). The between-hospital differences in SMR1 appeared substantial (interquartile range (IQR) 0-1.036), and they were even higher in SMR2 (IQR 0-1.19). SMR1 identified 7 hospitals as high-mortality outliers. SMR2 identified 4 hospitals as high-mortality outliers. Some hospitals went from non-outlier to high mortality and vice-versa. Kappa values were roughly 0.46 and indicated moderate agreement. CONCLUSION: We found that most hospitals provided Epithor with high-quality data, but other hospitals needed to improve the quality of the information provided. Quality control is essential for this type of database and necessary for the unbiased adjustment of regression models.