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410 citation(s) found for "Nair, AA".

Abstract 1944: Prognostic biomarkers for gallbladder cancer: A machine learning approach
Jackson, Linsey, Allotey, Loretta K., Kenneth, Valles, Nair, Asha, Athreya, Arjun P. , Oliver, Gavin R. , O'Brien, Daniel, Graham, Rondell P. , Borad, Mitesh J. , Roberts, Lewis R.

Cancer Research | June 15, 2022 | Volume: 82 | Issue: 12_Supplement | Pages: 1944-1944

10.1158/1538-7445.am2022-1944 Get It

Abstract Gallbladder cancer (GBC) is one of the deadliest cancers, with a 5-year-survival-rate of less than 5 percent for late-stage disease. The response rate to chemotherapy among GBC patients is generally poor. Recent research has attempted to identify diagnostic, prognostic, and predictive biomarkers, however, currently, no biomarkers can accurately diagnose GBC and predict patients’ prognosis. Integrative analysis of molecular and clinical characterization has not been fully established, and minimal improvement has been made to the survival of these patients, in part due to the heterogeneity of GBC. Machine learning techniques have been proven to empower analysis of big data in oncology, allowing for improvement in the generation of biomarkers to predict patient outcomes. Using machine learning, we can utilize high-throughput RNA sequencing with clinicopathologic data to develop a predictive tool for GBC prognosis. Current predictive models for GBC outcomes often utilize clinical data only, with the highest C-statistic reported being 0.71. C-statistic values over 0.7 generally indicate good models, however 0.8 is the threshold for strong predictive models. We aim to build a superior algorithm to predict overall survival in GBC patients with advanced disease, using machine learning approaches to prioritize biomarkers for GBC prognosis. We have identified over 80 fresh frozen GBC tissue samples from Mayo Clinic Rochester, Dongsan Medical Center in Daegu, Korea, University of the Witwatersrand, in Johannesburg, South Africa, Lithuanian University of Health Science in Vilnius, Lithuania, and University of Calgary in Calgary, Canada, from patients enrolled between 2012 and 2021. We will perform next-generation RNA sequencing on these tissue samples. The patients’ clinical, pathologic and survival data will be abstracted from the medical record uniformly across sites. Feature engineering and dimensionality reduction will be performed. Then random forests, support vector machines, and gradient boosting machines will be applied to train the data. Variable importance will prioritize multi-omic markers. Standard 5-fold cross validation will be used to assess performance of each ML algorithm. If overall survival can be better predicted with the addition patients’ transcriptional sequencing data compared to using clinical profiles alone, we can gain a greater understanding of key biomarkers driving the tumor phenotype. Citation Format: Linsey Jackson, Loretta Allotey, Valles Kenneth, Gavin Oliver, Asha Nair, Daniel O'Brien, Rondell Graham, Mitesh Borad, Arjun Athreya, Lewis Roberts. Prognostic biomarkers for gallbladder cancer: A machine learning approach [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1944.
The Effect of Glucagon on Protein Catabolism During Insulin Deficiency: Exchange of Amino Acids Across Skeletal Muscle and the Splanchnic Bed
James, Haleigh, Manjunatha, S , Dasari, Surendra , Klaus, Katherine A. , Vella, Adrian , Andrews, James C. , Nair, K. Sreekumaran , Manjunatha, Shankarappa, Lanza, Ian R , Vella, Adrian , Nair, K Sreekumaran , Gonsalves, Wilson I. , Lanza, Ian R.

Diabetes | May 27, 2022 | Volume: 71 | Issue: 8 | Pages: 1636-1648

10.2337/db22-0079 | PMID 35621914 Get It

Transient insulin deprivation with concurrent hyperglucagonemia is a catabolic state that can occur in type 1 diabetes. To evaluate glucagon’s catabolic effect in the setting of its glucogenic effect, we measured the regional exchanges of amino acid metabolites (amino-metabolites) across muscle and splanchnic beds in 16 healthy humans during either somatostatin followed by glucagon or saline infusion alone. Despite a twofold or greater increase in the regional exchange of amino-metabolites by glucagon, whole-body kinetics and concentrations of amino acids (AA) remained stable. Glucagon increased the splanchnic uptake of not only gluconeogenic but also essential (EAA) AA while increasing their release from the muscle bed. Regional tracer-based kinetics and 3-methylhistidine release indicate that EAA release from muscle is likely caused by reduced protein synthesis rather than increased protein degradation. Furthermore, many metabolites known to affect insulin action and metabolism were altered by hyperglucagonemia including increase in branched-chain AA and keto acids of leucine and isoleucine in arterial plasma. Further, an increase in arterial concentrations of α-aminoadipic acid arising from increased conversion from lysine in the splanchnic bed was noted. These results demonstrate that hyperglucagonemia during hypoinsulinemia increases net muscle protein catabolism and substantially increases the exchange of amino metabolites across splanchnic and muscle beds.
Predictive Modeling of New-Onset Postoperative Diplopia Following Orbital Decompression for Thyroid Eye Disease
Nair, Archana , Ediriwickrema, Lilangi S. , Dolman, Peter J. , Law, Geoffrey , Harrison, Andrew R. , Mokhtarzadeh, Ali , Stewart, Krista J., Men, Clara J. , Lucarelli, Mark J., Landingham, Suzanne van, Wingelaar, Maxwell , Verma, Rohan , Chen, Allison , Selva, Dinesh , Garrity, James, Eckel, Laurence J. , Kazim, Michael, Godfrey, Kyle J. , Korn, Bobby S. , Kikkawa, Don O. , Eckel, Laurence, Stewart, Krista, Landingham, Suzanne W. van , Baxter, Sally L.

Ophthalmic Plastic & Reconstructive Surgery | May 13, 2022 | Volume: 38 | Issue: 6 | Pages: 551-557

10.1097/iop.0000000000002196 | PMID 35551414 Get It

Purpose: To identify risk factors for the development of new-onset, postoperative diplopia following orbital decompression surgery based on patient demographics, clinical exam characteristics, radiographic parameters, and surgical techniques. Methods: We conducted a multi-center retrospective chart review of patients who underwent orbital decompression for thyroid eye disease (TED). Patient demographics, including age, gender, smoking history, preoperative exophthalmometry, clinical activity score (CAS), use of peribulbar and/or systemic steroids, and type of orbital decompression were reviewed. Postoperative diplopia was determined at a minimum of 3 months postoperatively and before any further surgeries. Cross-sectional area ratios of each extraocular muscle to orbit and total fat to orbit were calculated from coronal imaging in a standard fashion. All measurements were carried out using PACS imaging software. Multivariable logistic regression modeling was performed using Stata 14.2 (StataCorp, College Station, TX). Results: A total of 331 patients without preoperative diplopia were identified. At 3 months postoperatively, 249 patients had no diplopia whereas 82 patients developed diplopia. The average postoperative follow-up was 22 months (range 3–156) months. Significant preoperative clinical risk factors for postoperative diplopia included older age at surgery, proptosis, use of peribulbar or systemic steroids, elevated clinical activity score, and presence of preoperative compressive optic neuropathy. Imaging findings of enlarged cross-sectional areas of each rectus muscle to the overall orbital area also conferred a significant risk of postoperative diplopia. Regarding surgical factors, postoperative diplopia was more common among those undergoing medial wall decompression, bilateral orbital surgery, and balanced decompression, whereas endoscopic medial wall decompression was found to be relatively protective. Conclusions: This study identifies risk factors associated with the development of diplopia following orbital decompression using multivariable data. This study demonstrates that several characteristics including age, clinical activity score, the cross-sectional muscle to orbit ratios, in addition to the type of orbital decompression surgery, are predictive factors for the development of new-onset postoperative diplopia.
Development and Validation of a Kidney-Transplant Specific Measure of Treatment Burden
Lorenz, Elizabeth C. , Petterson, Tanya M. , Lackore, Kandace A. , Johnson, Bradley K. , Mai, Martin L., Nair, S. , Yost, Kathleen J. , Zaniletti, Isabella , Mai, Martin L., Bentall, Andrew , Eton, David T.

No container title available | May 6, 2022 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.21203/rs.3.rs-1601974/v1 Get It

Abstract Background Treatment burden refers to the work involved in managing one’s health and its impact on well-being and has been associated with nonadherence in patients with chronic illnesses. No kidney transplant (KT)-specific measure of treatment burden exists. The aim of this study was to develop a KT-specific supplement to the Patient Experience with Treatment and Self-Management (PETS), a general measure of treatment burden. Methods After drafting and pretesting KT-specific survey items, we conducted a cross-sectional survey study involving KT recipients from Mayo Clinic in Minnesota, Arizona, and Florida. Exploratory factor analysis (EFA) was used to identify domains for scaling the KT-specific supplement. Construct and known-groups validity were determined. Results Survey respondents (n = 167) had a mean age of 61 years (range 22–86) and received a KT on average 4.0 years ago. Three KT-specific scales were identified (transplant function, self-management, adverse effects). Higher scores on the KT-specific scales were correlated with higher PETS treatment burden, worse physical and mental health, and lower self-efficacy (p < 0.0001). Patients taking more medications reported higher transplant self-management burden. Conclusions We developed a KT-specific supplement to the PETS general measure of treatment burden. Scores may help providers identify recipients at risk for nonadherence.
Differential mRNA expression in ileal and colonic biopsies in irritable bowel syndrome with diarrhea or constipation
Camilleri, Michael , Magnus, Yorick, Carlson, Paula, Chedid, Victor , Maselli, Daniel B. , Taylor, Ann, McKinzie, Sanna, Nagaraj, Nagaswaroop Kengunte , Busciglio, Irene, Nair, Asha, Kengunte Nagaraj, Nagaswaroop, Chedid, Victor G , Wang, Xiao‐Jing

American Journal of Physiology-Gastrointestinal and Liver Physiology | May 3, 2022 | Volume: 323 | Issue: 2 | Pages: G88-G101

10.1152/ajpgi.00063.2022 | PMID 35502856 Get It

This study compares gene expression in mucosa of the terminal ileum, right colon, and left colon in patients with diarrhea- or constipation-predominant irritable bowel syndrome (IBS) and contrasts expression between these two disease entities and also between each entity and mucosa from healthy controls. The study shows there is differential expression of genes related to immune, transmitter, nociceptive, ion channel, and transporter functions, as well as reduced serine protease inhibition, in patients with IBS.
Deletion of the Vitamin D Receptor in Skeletal Muscle is Associated with Improved Glucose Tolerance and Reduced Muscle Function
Losbanos, Louis, Craig, Theodore A., Fadra, Numrah, Nair, Asha, Matveyenko, Aleksey V. , Kumar, Rajiv

The FASEB Journal | May 3, 2022 | Volume: 36 | Issue: S1 | Pages: No page available

10.1096/fasebj.2022.36.s1.r3545 Get It

Skeletal muscle insulin resistance contributes to the pathogenesis of type 2 diabetes mellitus. Epidemiological studies have demonstrated that vitamin D deficiency is associated with the presence of type 2 diabetes in humans. To probe the role of the vitamin D receptor (VDR), an intracellular and nuclear protein that mediates the bioactivity of the active vitamin D ligand, 1,25‐dihydroxyvitamin D, in skeletal muscle mediated glucose disposal, we deleted the skeletal muscle VDR in adult mice. We assessed glucose disposal, insulin concentrations and sensitivity, and skeletal muscle gene expression in Vdr knockout and wild‐type Vdr mice. Following the induction of a skeletal muscle‐specific Cre recombinase with tamoxifen in adult male Vdr fl/fl mice, efficient deletion of the Vdr was demonstrated. In skeletal muscle‐specific Vdr knockout mice, basal glucose concentrations were similar to those in wild‐type Vdr mice. In Vdr knockout mice, blood glucose concentrations decreased more rapidly following the administration of intraperitoneal glucose than in control mice expressing wild‐type Vdr (Figure 1A and Figure 1B). The AUC for glucose concentrations in Vdr fl/fl .actin iCre mice treated with tamoxifen was reduced by 20% (p=0.015) compared to the AUC of blood glucose concentrations prior to tamoxifen treatment. Pre‐and post‐treatment AUC’s for blood glucose in Vdr fl/fl .actin iCre mice treated with vehicle and in Vdr fl/fl mice treated with tamoxifen were unchanged (p=0.97,0.23). Plasma insulin concentrations were identical in knockout and wild‐type Vdr mice following a bolus of glucose, demonstrating that deletion of the Vdr in skeletal muscle did not influence the release of insulin in response to glucose (one‐way ANOVA, p=0.45). Insulin sensitivity was similar in Vdr knockout and wild‐type Vdr mice. Gene expression analysis of skeletal muscle mRNA derived from Vdr knockout mice and wild‐type mice demonstrated an increase in the expression of genes associated with oxidative phosphorylation, fatty acid oxidation and adipogenesis pathways that could potentially alter glucose utilization. We conclude that selective deletion of the Vdr in the skeletal muscle of adult mice results in more efficient glucose disposal than in wild‐type Vdr mice; basal and glucose‐stimulated insulin serum concentrations are identical in knock‐out and wild type VDR mice with no changes in insulin sensitivity. The data suggest that modulation of the vitamin‐D endocrine system is unlikely to improve glucose utilization.
Quantitative analysis of visually reviewed normal scalp EEG predicts seizure freedom following anterior temporal lobectomy
Varatharajah, Yogatheesan , Brinkmann, Benjamin H. , Morita‐Sherman, Marcia , Fitzgerald, Zachary , Vegh, Deborah , Nair, Dileep , Burgess, Richard C. , Cendes, Fernando , Jehi, Lara , Joseph, Boney , Brinkmann, Benjamin H , Fitzgerald, Zachary , Cendes, Fernando , Jehi, Lara , Nair, Dileep R , Joseph, Boney , Morita, Márcia Elisabete , Worrell, Gregory A.

Epilepsia | April 13, 2022 | Volume: 63 | Issue: 7 | Pages: 1630-1642

10.1111/epi.17257 | PMID 35416285 Get It

Abstract Objective Anterior temporal lobectomy (ATL) is a widely performed and successful intervention for drug‐resistant temporal lobe epilepsy (TLE). However, up to one third of patients experience seizure recurrence within 1 year after ATL. Despite the extensive literature on presurgical electroencephalography (EEG) and magnetic resonance imaging (MRI) abnormalities to prognosticate seizure freedom following ATL, the value of quantitative analysis of visually reviewed normal interictal EEG in such prognostication remains unclear. In this retrospective multicenter study, we investigate whether machine learning analysis of normal interictal scalp EEG studies can inform the prediction of postoperative seizure freedom outcomes in patients who have undergone ATL. Methods We analyzed normal presurgical scalp EEG recordings from 41 Mayo Clinic (MC) and 23 Cleveland Clinic (CC) patients. We used an unbiased automated algorithm to extract eyes closed awake epochs from scalp EEG studies that were free of any epileptiform activity and then extracted spectral EEG features representing (a) spectral power and (b) interhemispheric spectral coherence in frequencies between 1 and 25 Hz across several brain regions. We analyzed the differences between the seizure‐free and non–seizure‐free patients and employed a Naïve Bayes classifier using multiple spectral features to predict surgery outcomes. We trained the classifier using a leave‐one‐patient‐out cross‐validation scheme within the MC data set and then tested using the out‐of‐sample CC data set. Finally, we compared the predictive performance of normal scalp EEG‐derived features against MRI abnormalities. Results We found that several spectral power and coherence features showed significant differences correlated with surgical outcomes and that they were most pronounced in the 10–25 Hz range. The Naïve Bayes classification based on those features predicted 1‐year seizure freedom following ATL with area under the curve (AUC) values of 0.78 and 0.76 for the MC and CC data sets, respectively. Subsequent analyses revealed that (a) interhemispheric spectral coherence features in the 10–25 Hz range provided better predictability than other combinations and (b) normal scalp EEG‐derived features provided superior and potentially distinct predictive value when compared with MRI abnormalities (>10% higher F1 score). Significance These results support that quantitative analysis of even a normal presurgical scalp EEG may help prognosticate seizure freedom following ATL in patients with drug‐resistant TLE. Although the mechanism for this result is not known, the scalp EEG spectral and coherence properties predicting seizure freedom may represent activity arising from the neocortex or the networks responsible for temporal lobe seizure generation within vs outside the margins of an ATL.
Latent Pulmonary Vascular Disease May Alter the Response to Therapeutic Atrial Shunt Device in Heart Failure
Borlaug, Barry A. , Blair, John, Bergmann, Martin W., Bugger, Heiko, Burkhoff, Daniel , Bruch, Leonhard , Celermajer, David S. , Claggett, Brian , Cleland, John G.F., Cutlip, Donald E. , Dauber, Ira, Eicher, Jean-Christophe , Gao, Qi, Gorter, Thomas M. , Gustafsson, Finn , Heyden, Jan van der, Hasenfuß, Gerd, Hummel, Scott L. , Komtebedde, Jan, Mazurek, Jeremy A., McKenzie, Scott , Mehta, Shamir R. , Petrie, Mark C. , Post, Marco C., Nair, Ajith, Rieth, Andreas , Silvestry, Frank E., Solomon, Scott D. , Trochu, Jean‐Noël , Veldhuisen, Dirk J. Van, Westenfeld, Ralf, Leon, Martin B., Investigators, on behalf of the REDUCE LAP-HF-II, Bugger, Heiko , Nair, Ajith , Burkhoff, Daniel , Hayward, Chris , Hummel, Scott L , Kaye, David M , Massaro, Joseph M. , McKenzie, Scott , Mehta, Shamir R , Petrie, Mark C , Rieth, Andreas , Solomon, Scott David , Trochu, Jean-Noël , Shah, Sanjiv J , Borlaug, Barry A , Nair, Ajith P , Celermajer, David , Gustafsson, Finn , Blair, John, Bergmann, Martin W., Bruch, Leonhard , Claggett, Brian L , Cleland, John G.F., Cutlip, Donald E. , Dauber, Ira, Eicher, Jean-Christophe , Gao, Qi, Gorter, Thomas M. , Heyden, Jan van der, Hasenfuß, Gerd, Komtebedde, Jan, Mazurek, Jeremy A., Post, Marco C., Nair, Ajith, Silvestry, Frank E., Veldhuisen, Dirk J. Van, Westenfeld, Ralf, Leon, Martin B., Investigators, on behalf of the REDUCE LAP-HF-II

Circulation | March 31, 2022 | Volume: 145 | Issue: 21 | Pages: 1592-1604

10.1161/circulationaha.122.059486 | PMID 35354306 Get It

Background: In REDUCE LAP-HF II (A Study to Evaluate the Corvia Medical, Inc IASD System II to Reduce Elevated Left Atrial Pressure in Patients With Heart Failure), implantation of an atrial shunt device did not provide overall clinical benefit for patients with heart failure with preserved or mildly reduced ejection fraction. However, prespecified analyses identified differences in response in subgroups defined by pulmonary artery systolic pressure during submaximal exercise, right atrial volume, and sex. Shunt implantation reduces left atrial pressures but increases pulmonary blood flow, which may be poorly tolerated in patients with pulmonary vascular disease (PVD). On the basis of these results, we hypothesized that patients with latent PVD, defined as elevated pulmonary vascular resistance during exercise, might be harmed by shunt implantation, and conversely that patients without PVD might benefit. Methods: REDUCE LAP-HF II enrolled 626 patients with heart failure, ejection fraction ≥40%, exercise pulmonary capillary wedge pressure ≥25 mm Hg, and resting pulmonary vascular resistance <3.5 Wood units who were randomized 1:1 to atrial shunt device or sham control. The primary outcome—a hierarchical composite of cardiovascular death, nonfatal ischemic stroke, recurrent HF events, and change in health status—was analyzed using the win ratio. Latent PVD was defined as pulmonary vascular resistance ≥1.74 Wood units (highest tertile) at peak exercise, measured before randomization. Results: Compared with patients without PVD (n=382), those with latent PVD (n=188) were older, had more atrial fibrillation and right heart dysfunction, and were more likely to have elevated left atrial pressure at rest. Shunt treatment was associated with worse outcomes in patients with PVD (win ratio, 0.60 [95% CI, 0.42, 0.86]; P =0.005) and signal of clinical benefit in patients without PVD (win ratio, 1.31 [95% CI, 1.02, 1.68]; P =0.038). Patients with larger right atrial volumes and men had worse outcomes with the device and both groups were more likely to have pacemakers, heart failure with mildly reduced ejection fraction, and increased left atrial volume. For patients without latent PVD or pacemaker (n=313; 50% of randomized patients), shunt treatment resulted in more robust signal of clinical benefit (win ratio, 1.51 [95% CI, 1.14, 2.00]; P =0.004). Conclusions: In patients with heart failure with preserved or mildly reduced ejection fraction, the presence of latent PVD uncovered by invasive hemodynamic exercise testing identifies patients who may worsen with atrial shunt therapy, whereas those without latent PVD may benefit.
Abstract 23085: 30-Day Outcomes of Transseptal Transcatheter Mitral Valve Replacement for Failed Surgical Bioprostheses (Mitral Valve-in-Valve): The MITRAL Trial (Mitral Implantation of TRAnscatheter vaLves)
Salinger, Michael H., Kodali, Susheel , Satler, Lowell F. , Inglessis, Ignacio, Eleid, Mackram F. , Meduri, Christopher, Rajagopal, Vivek , Reisman, Mark, Aldea, Gabriel S. , Eng, Marvin H. , Waksman, Ron , Pichard, Augusto D., Palacios, Igor F. , Russell, Hyde M., Saucedo, Jorge , Makkar, Raj , Rihal, Charanjit S. , Leon, Martin B. , Feldman, Ted , Guerrero, Mayra , Pursnani, Amit , Wang, Dee Dee , George, Isaac , Hahn, Rebecca T , Kar, Saibal , O’Neill, William W. , Rihal, Charanjit S.

Circulation | March 19, 2022 | Volume: 136 | Issue: suppl_1 | Pages: No page available

10.1161/circ.136.suppl_1.23085 Get It

Introduction: Transcatheter mitral valve replacement (TMVR) using aortic transcatheter heart valves (THV) is developing as an alternative to surgery for patients with severely degenerated mitral valve (MV) bioprostheses. Retrospective self-reported registries have collected outcomes on these TMVR procedures in the STS/ACC Transcatheter Valve Therapy Registry and in the Valve-in-Valve International Database. Most reported TMVR procedures for failed surgical bioprostheses have been performed using a transapical access approach. A prospective comprehensive evaluation of mitral Valve-in-Valve (VIV) outcomes, including transseptal access has not previously been conducted. Objectives: To evaluate in-hospital and 30-day clinical outcomes of transseptal mitral VIV with SAPIEN 3 THV in patients with very high surgical risk. Methods: Prospective enrollment of very high surgical risk patients with symptomatic severely degenerated MV surgical bioprostheses in 30 patients at 15 sites in the U.S. Candidates were assessed by a case review committee prior to approval. Baseline qualifying echocardiograms and cardiac CT studies were analyzed by independent core labs. Echocardiograms, cardiac CT studies and neurology evaluations were also performed after mitral VIV procedures. Clinical events were adjudicated by a clinical events committee and safety was monitored by a data safety monitoring board. Results: 26 patients have been enrolled between July 2016 and June 2017. Mean age was 83 years, 62% female, mean STS score was 10% and 62% were in New York Heart Association class III or IV. Transseptal access was used in all procedures. Technical success was achieved in all patients and there was no in-hospital mortality. There was no 30-day cardiovascular mortality and 4% (1 patient) 30-day all-cause mortality (1 patient died of asphyxia on day 29 after choking on pills at home), which was lower than the 30-day mortality in the TVT registry (9%). Detailed procedural, in-hospital and 30-day outcomes will be presented on the complete cohort of 30 patients. Conclusions: In patients without surgical alternatives, transseptal mitral ViV procedures in failed surgical bioprostheses are associated with high technical and procedural success and low 30-day mortality.