Faculty Bibliography

In lung cancer, enrichment of the lower airway microbiota with oral commensals commonly occurs and ex vivo models support that some of these bacteria can trigger host transcriptomic signatures associated with carcinogenesis. Here, we show that this lower airway dysbiotic signature was more prevalent in group IIIB-IV TNM stage lung cancer and is associated with poor prognosis, as shown by decreased survival among subjects with early stage disease (I-IIIA) and worse tumor progression as measured by RECIST scores among subjects with IIIB-IV stage disease. In addition, this lower airway microbiota signature was associated with upregulation of IL-17, PI3K, MAPK and ERK pathways in airway transcriptome, and we identified Veillonella parvula as the most abundant taxon driving this association. In a KP lung cancer model, lower airway dysbiosis with V. parvula led to decreased survival, increased tumor burden, IL-17 inflammatory phenotype and activation of checkpoint inhibitor markers.

BACKGROUND:Platelets are increasingly recognized as immune cells. As such, they are commonly seen to induce and perpetuate inflammation, however, anti-inflammatory activities are increasingly attributed to them. Atherosclerosis is a chronic inflammatory condition. Similar to other inflammatory conditions, the resolution of atherosclerosis requires a shift in macrophages to an M2 phenotype, enhancing their efferocytosis and cholesterol efflux capabilities. OBJECTIVES/OBJECTIVE:To assess the effect of platelets on macrophage phenotype. METHODS:In several in vitro models employing murine (RAW264.7 and bone marrow derived macrophages) and human (THP-1 and monocyte-derived macrophages) cells, we exposed macrophages to media in which non-agonized human platelets were cultured for 60 minutes (platelet conditioned media; PCM) and assessed the impact on macrophage phenotype and function. RESULTS:). CONCLUSIONS:PCM induces an anti-inflammatory, pro-resolving phenotype in macrophages. Our findings suggest that therapies targeting hemostatic properties of platelets, while not influencing pro-resolving, immune-related activities, could be beneficial for the treatment of atherothrombotic disease.

The microbiome plays a major role in human physiology by influencing obesity, inducing inflammation, and impacting cancer therapies. During the 60th Annual Meeting of the Society of the Alimentary Tract (SSAT) at the State-of-the-Art Conference, experts in the field discussed the influence of the microbiome. This paper is a summary of the influence of the microbiome on obesity, inflammatory bowel disease, pancreatic cancer, cancer therapies, and gastrointestinal optimization. This review shows how the microbiome plays an important role in the development of diseases and surgical complications. Future studies are needed in targeting the gut microbiome to develop individualized therapies.

Barth Syndrome (BTHS) is a rare X-linked genetic disorder caused by mutations in the gene encoding the transacylase tafazzin and characterized by loss of cardiolipin and severe cardiomyopathy. Mitochondrial oxidants have been implicated in the cardiomyopathy in BTHS. Eleven mitochondrial sites produce superoxide/H₂ O₂ at significant rates. Which of these sites generate oxidants at excessive rates in BTHS is unknown. Here, we measured the maximum capacity of superoxide/H₂ O₂ production from each site and the ex vivo rate of superoxide/H₂ O₂ production in the heart and skeletal muscle mitochondria of the tafazzin knockdown mice (tazkd) from 3 to 12 months of age. Despite reduced oxidative capacity, superoxide/H₂ O₂ production is indistinguishable between tazkd mice and wildtype littermates. These observations raise questions about the involvement of mitochondrial oxidants in BTHS pathology.

Many military veterans who experienced blast-related traumatic brain injuries (TBI) in the conflicts in Iraq and Afghanistan currently suffer from chronic cognitive and mental health problems including post-traumatic stress disorder (PTSD). Besides static symptoms, new symptoms may emerge or existing symptoms may worsen. TBI is also a risk factor for the later development of neurodegenerative diseases. Rats exposed to repetitive low-level blast overpressure (BOP) develop robust and enduring cognitive and PTSD-related behavioral traits that are present for at least one year after blast exposure. Here we determined the time-course of these traits appearance by testing rats in the immediate post-blast period. Three cohorts of rats examined within the first eight weeks exhibited no behavioral phenotype, or in one cohort features of anxiety. None showed the altered cued fear responses, or impaired novel object recognition characteristic of the fully developed phenotype. Two cohorts retested 36 to 42 weeks after blast exposure exhibited the expanded behavioral phenotype including anxiety as well as altered cued fear learning and impaired novel object recognition. Combined with previous work the chronic behavioral phenotype has been observed in six cohorts of blast-exposed rats studied at 3-4 months or longer after blast injury and the three cohorts studied here document the progressive nature of the cognitive/behavioral phenotype. These studies suggest the existence of a latent, delayed emerging, and progressive blast-induced cognitive and behavioral phenotype. The delayed onset has implications for the evolution of post-blast neurobehavioral syndromes in military veterans and its modeling in experimental animals.

Leginon is a system for automated data acquisition from a transmission electron microscope. Here we provide an updated summary of the overall Leginon architecture and an update of the current state of the package. We also highlight a few recent developments to provide some concrete examples and use cases. This article is protected by copyright. All rights reserved.

KRAS is the most frequently mutated human oncogene, and KRAS inhibition has been a longtime goal. Recently, inhibitors were developed that bind KRASG12C-GDP and react with Cys-12 (G12C-Is). Using new affinity reagents to monitor KRASG12C activation and inhibitor engagement, we found that an SHP2 inhibitor (SHP2-I) increases KRAS-GDP occupancy, enhancing G12C-I efficacy. The SHP2-I abrogated RTK feedback signaling and adaptive resistance to G12C-Is in vitro, in xenografts, and in syngeneic KRASG12C-mutant pancreatic ductal adenocarcinoma (PDAC) and non-small cell lung cancer (NSCLC). SHP2-I/G12C-I combination evoked favorable but tumor site-specific changes in the immune microenvironment, decreasing myeloid suppressor cells, increasing CD8+ T cells, and sensitizing tumors to PD-1 blockade. Experiments using cells expressing inhibitor-resistant SHP2 showed that SHP2 inhibition in PDAC cells is required for PDAC regression and remodeling of the immune microenvironment but revealed direct inhibitory effects on tumor angiogenesis and vascularity. Our results demonstrate that SHP2-I/G12C-I combinations confer a substantial survival benefit in PDAC and NSCLC and identify additional potential combination strategies.

OBJECTIVE:Endovascular abdominal aortic aneurysm repair (EVAR) is preferred to open surgical repair (OSR) for the treatment of abdominal aortic aneurysm (AAA) in high-risk patients. We sought to compare perioperative and long-term outcomes for EVAR in patients designated as unfit for OSR using a large national dataset. METHODS:The Vascular Quality Initiative database collected from 2013 to 2019 was queried for patients undergoing elective EVARs for AAA > 5cm. The patients were stratified into two cohorts based on the suitability for OSR (FIT vs. UNFIT). Primary outcomes included perioperative (in-hospital) major adverse events, perioperative mortality, and mortality at 1 and 5 years. Patient demographics and postoperative outcomes were analyzed to identify predictors of perioperative and long-term mortality. RESULTS:Of 16,183 EVARs, 1,782 patients were deemed unfit for OSR. The UNFIT cohort was more likely to be older and female, with higher proportions of HTN, CAD, CHF, COPD, and larger aneurysm diameter. Postoperatively, the UNFIT cohort was more likely to have cardiopulmonary complications (6.5% vs. 3%; P<.001), with higher perioperative mortality (1.7% vs. 0.6%; P<.001) and 1 and 5-year mortality (13% and 29% UNFIT vs. 5% and 14% FIT; P<.001). Subgroup analysis within the UNFIT cohort revealed those deemed unfit due to hostile abdomen had significantly lower 1 and 5-year mortality (6% and 20%) compared to those unfit due to cardiopulmonary compromise and frailty (14% and 30%; P=.451). Reintervention-free survival at 1 and 5-years was significantly higher in the FIT cohort (93% and 82%) as compared to the UNFIT cohort (85% and 68%; P<.001). Designation as unfit for OSR was an independent predictor of both perioperative (OR 1.59; 95% CI, 1.03-2.46; P=.038) and long-term mortality (HR 1.92; 95% CI, 1.69-2.17; P<.001). Advanced age (OR 2.91; 95% CI, 1.28-6.66; P=.011) was the strongest determinant of perioperative mortality while ESRD (HR 2.51; 95% CI, 1.78-3.55; P<.001) was the strongest predictor of long-term mortality. Statin (HR 0.77; 95% CI, 0.69-0.87; P<.001) and ACE inhibitor (HR 0.83; 95% CI, 0.75-0.93; P<.001) were protective of long-term mortality. CONCLUSION/CONCLUSIONS:Despite low perioperative mortality, long-term mortality of those designated by the operating surgeons as unfit for OSR was rather high in patients undergoing elective EVARs, likely due to the competing risk of death from their medical frailty. Unfit designation due to hostile abdomen did not confer any additional risks after EVAR. Judicious estimation of the patient's life expectancy is essential when considering treatment options in this subset of patients deemed unfit for OSR.

BACKGROUND:The therapeutic effect of carotid endarterectomy (CEA) on visual disturbance caused by chronic ocular ischemia due to carotid artery stenosis has not been validated. This prospective observational study aims to investigate whether CEA is associated with an increase in ocular blood flow (OBF) and postoperative visual improvement. METHODS:In total, 41 patients with carotid artery stenosis treated by CEA between March 2015 and September 2018 were enrolled in this study. OBF was evaluated by laser speckle flowgraphy, which can measure the mean blur ratio (MBR) which is well correlated to the absolute retinal blood flow. Visual acuity was assessed before and after CEA by subjective improvement and objective visual assessment using CSV-1000, an instrument used to test contrast sensitivity. RESULTS:OBF increased after CEA on the operated side (mean MBR 33.5 vs 38.2, p < 0.001) but not on the non-operated side (mean MBR 37.8 vs 37.5, p = 0.50). After CEA, 23 patients (56.1%) reported subjective visual improvement on the operated side. The mean CSV-1000 score among the patients with increased OBF after CEA (5.44 vs 5.88, p = 0.04) but not among those without increased OBF (5.48 vs 5.95, p = 0.09). The mean CSV-1000 scores increased significantly after CEA in 18 patients with decreased vision and decreased OBF (4.51 vs 5.37, p < 0.001), but not in the 23 patients without those (6.19 vs 6.31, p = 0.6). CONCLUSION/CONCLUSIONS:CEA may successfully reverse visual dysfunction caused by chronic ocular ischemia due to carotid artery stenosis by increasing OBF.

STUDY DESIGN/METHODS:Retrospective analysis using the PearlDiver national insurance claims database. OBJECTIVE:To investigate the relationship between chronic preoperative selective serotonin reuptake inhibitor (SSRI) prescriptions and nonunion following spine fusion surgery. SUMMARY OF BACKGROUND DATA/BACKGROUND:Contemporary literature has linked SSRIs to decreased bone mineral density and increased rates of future bone fracture. Furthermore, a recent murine model has suggested a potential role in the quality of fracture healing itself. METHODS:All single-level lumbar fusion patients were identified. The rate of nonunion diagnosis between 6 and 24 months following surgery was assessed. A stratified analysis of chronic SSRI use and a number of comorbidities was conducted, followed by a multiple logistic regression analysis of nonunion accounting for qualifying risk factors. Finally, subanalyses of individual procedure codes were carried out. RESULTS:In total, 7905 single-level lumbar fusion patients were included. In the multivariate analysis, chronic SSRI [odds ratio (OR): 1.558, P=0.004] and tobacco use (OR: 1.500, P=0.011) were identified as independent risk factors for nonunion, whereas patient age over 60 years (OR: 0.468, P<0.001) was observed to be negatively associated with nonunion. In the individual procedure subanalyses, SSRIs were significantly associated with nonunion in 2 of 3 univariate analyses and observed to be an independent risk factor for nonunion in 2 of the 3 procedure populations. CONCLUSIONS:These data suggest that patients treated concomitantly for mental health disorders with SSRIs before arthrodesis may be at an increased risk of postoperative nonunion. Closer follow-up may be indicated in this patient population.