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Dive into the research topics where Sitaram Vangala is active.

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Featured researches published by Sitaram Vangala.


Heart Rhythm | 2015

FREEDOM FROM RECURRENT VENTRICULAR TACHYCARDIA AFTER CATHETER ABLATION IS ASSOCIATED WITH IMPROVED SURVIVAL IN PATIENTS WITH STRUCTURAL HEART DISEASE: AN INTERNATIONAL VT ABLATION CENTER COLLABORATIVE GROUP STUDY

Roderick Tung; Marmar Vaseghi; David S. Frankel; Pasquale Vergara; Luigi Di Biase; Koichi Nagashima; Ricky Yu; Sitaram Vangala; Chi Hong Tseng; Eue Keun Choi; Shaan Khurshid; Mehul Patel; Nilesh Mathuria; Shiro Nakahara; Wendy S. Tzou; William H. Sauer; Kairav Vakil; Usha B. Tedrow; J. David Burkhardt; Venkatakrishna N. Tholakanahalli; Anastasios Saliaris; Timm Dickfeld; J. Peter Weiss; T. Jared Bunch; Madhu Reddy; Arun Kanmanthareddy; David J. Callans; Dhanunjaya Lakkireddy; Andrea Natale; Francis E. Marchlinski

BACKGROUND The impact of catheter ablation of ventricular tachycardia (VT) on all-cause mortality remains unknown. OBJECTIVE The purpose of this study was to examine the association between VT recurrence after ablation and survival in patients with scar-related VT. METHODS Analysis of 2061 patients with structural heart disease referred for catheter ablation of scar-related VT from 12 international centers was performed. Data on clinical and procedural variables, VT recurrence, and mortality were analyzed. Kaplan-Meier analysis was used to estimate freedom from recurrent VT, transplant, and death. Cox proportional hazards frailty models were used to analyze the effect of risk factors on VT recurrence and mortality. RESULTS One-year freedom from VT recurrence was 70% (72% in ischemic and 68% in nonischemic cardiomyopathy). Fifty-seven patients (3%) underwent cardiac transplantation, and 216 (10%) died during follow-up. At 1 year, the estimated rate of transplant and/or mortality was 15% (same for ischemic and nonischemic cardiomyopathy). Transplant-free survival was significantly higher in patients without VT recurrence than in those with recurrence (90% vs 71%, P<.001). In multivariable analysis, recurrence of VT after ablation showed the highest risk for transplant and/or mortality [hazard ratio 6.9 (95% CI 5.3-9.0), P<.001]. In patients with ejection fraction <30% and across all New York Heart Association functional classes, improved transplant-free survival was seen in those without VT recurrence. CONCLUSION Catheter ablation of VT in patients with structural heart disease results in 70% freedom from VT recurrence, with an overall transplant and/or mortality rate of 15% at 1 year. Freedom from VT recurrence is associated with improved transplant-free survival, independent of heart failure severity.


International Journal of Eating Disorders | 2015

Altered interoceptive awareness in anorexia nervosa: Effects of meal anticipation, consumption and bodily arousal

Sahib S. Khalsa; Michelle G. Craske; Wei Li; Sitaram Vangala; Michael Strober; Jamie D. Feusner

OBJECTIVE Impaired interoceptive awareness (IA), the subjective perception of internal body sensations, has been proposed as a vulnerability or maintaining factor in anorexia nervosa (AN). We examined whether IA of heartbeat and breathing sensations was impaired in AN across a range of arousal levels, and whether it was influenced by meal anticipation and consumption. METHOD IA was assessed using randomized, double-blinded, bolus intravenous infusions of isoproterenol, a peripheral beta-adrenergic sympathetic agonist, and saline. Fifteen women with AN and 15 age-, and sex- matched healthy comparisons (HC) were evaluated before and after consumption of a 1,000 Calorie meal. During each infusion participants rated their moment-to-moment intensity of heartbeat and breathing sensations with a dial. To measure IA we evaluated interoceptive detection thresholds, retrospective ratings of palpitation and dyspnea intensity, and interoceptive accuracy via correlations between subjective dial ratings and observed heart rate responses. RESULTS Contrary to prediction the AN group was more likely to report detection of interoceptive sensations across all conditions, an effect driven by false discriminations at low arousal levels. Concordant with prediction, meal anticipation was associated with intensified interoceptive sensations, particularly dyspnea. There were no differences in interoceptive accuracy. DISCUSSION This represents the first demonstration of interoceptive prediction errors in AN. Although IA is unimpaired at high arousal levels in AN, prediction signals are abnormal at low arousal levels, especially during meal anticipation. Altered interoceptive prediction signaling during meal anticipation could contribute to phenotypes of high anxiety in AN or alternatively, might be explained by enhanced meal associated anxiety.


Brain | 2015

Early behavioural changes in familial Alzheimer’s disease in the Dominantly Inherited Alzheimer Network

John M. Ringman; Li Jung Liang; Yan Zhou; Sitaram Vangala; Edmond Teng; Sarah Kremen; David Wharton; Alison Goate; Daniel S. Marcus; Martin R. Farlow; Bernardino Ghetti; Eric McDade; Colin L. Masters; Richard Mayeux; Stephen Salloway; Peter R. Schofield; Jeffrey L. Cummings; Virginia Buckles; Randall J. Bateman; John C. Morris

Prior studies indicate psychiatric symptoms such as depression, apathy and anxiety are risk factors for or prodromal symptoms of incipient Alzheimers disease. The study of persons at 50% risk for inheriting autosomal dominant Alzheimers disease mutations allows characterization of these symptoms before progressive decline in a population destined to develop illness. We sought to characterize early behavioural features in carriers of autosomal dominant Alzheimers disease mutations. Two hundred and sixty-one persons unaware of their mutation status enrolled in the Dominantly Inherited Alzheimer Network, a study of persons with or at-risk for autosomal dominant Alzheimers disease, were evaluated with the Neuropsychiatric Inventory-Questionnaire, the 15-item Geriatric Depression Scale and the Clinical Dementia Rating Scale (CDR). Ninety-seven asymptomatic (CDR = 0), 25 mildly symptomatic (CDR = 0.5), and 33 overtly affected (CDR > 0.5) autosomal dominant Alzheimers disease mutation carriers were compared to 106 non-carriers with regard to frequency of behavioural symptoms on the Neuropsychiatric Inventory-Questionnaire and severity of depressive symptoms on the Geriatric Depression Scale using generalized linear regression models with appropriate distributions and link functions. Results from the adjusted analyses indicated that depressive symptoms on the Neuropsychiatric Inventory-Questionnaire were less common in cognitively asymptomatic mutation carriers than in non-carriers (5% versus 17%, P = 0.014) and the odds of experiencing at least one behavioural sign in cognitively asymptomatic mutation carriers was lower than in non-carriers (odds ratio = 0.50, 95% confidence interval: 0.26-0.98, P = 0.042). Depression (56% versus 17%, P = 0.0003), apathy (40% versus 4%, P < 0.0001), disinhibition (16% versus 2%, P = 0.009), irritability (48% versus 9%, P = 0.0001), sleep changes (28% versus 7%, P = 0.003), and agitation (24% versus 6%, P = 0.008) were more common and the degree of self-rated depression more severe (mean Geriatric Depression Scale score of 2.8 versus 1.4, P = 0.006) in mildly symptomatic mutation carriers relative to non-carriers. Anxiety, appetite changes, delusions, and repetitive motor activity were additionally more common in overtly impaired mutation carriers. Similar to studies of late-onset Alzheimers disease, we demonstrated increased rates of depression, apathy, and other behavioural symptoms in the mildly symptomatic, prodromal phase of autosomal dominant Alzheimers disease that increased with disease severity. We did not identify any increased psychopathology in mutation carriers over non-carriers during the presymptomatic stage, suggesting these symptoms result when a threshold of neurodegeneration is reached rather than as life-long qualities. Unexpectedly, we found lower rates of depressive symptoms in cognitively asymptomatic mutation carriers.


PLOS ONE | 2013

The CD44high Tumorigenic Subsets in Lung Cancer Biospecimens Are Enriched for Low miR-34a Expression

Saroj K. Basak; Mysore S. Veena; Scott Oh; Chi Lai; Sitaram Vangala; David Elashoff; Michael C. Fishbein; Sanjai Sharma; Nagesh Rao; Dinesh S. Rao; Ryan Phan; Eri S. Srivatsan; Raj K. Batra

Cellular heterogeneity is an integral part of cancer development and progression. Progression can be associated with emergence of cells that exhibit high phenotypic plasticity (including “de-differentiation” to primitive developmental states), and aggressive behavioral properties (including high tumorigenic potentials). We observed that many biomarkers that are used to identify Cancer Stem Cells (CSC) can label cell subsets in an advanced clinical stage of lung cancer (malignant pleural effusions, or MPE). Thus, CSC-biomarkers may be useful for live sorting functionally distinct cell subsets from individual tumors, which may enable investigators to hone in on the molecular basis for functional heterogeneity. We demonstrate that the CD44hi (CD44-high) cancer cell subsets display higher clonal, colony forming potential than CD44lo cells (n = 3) and are also tumorigenic (n = 2/2) when transplanted in mouse xenograft model. The CD44hi subsets express different levels of embryonal (de-differentiation) markers or chromatin regulators. In archived lung cancer tissues, ALDH markers co-localize more with CD44 in squamous cell carcinoma (n = 5/7) than Adeno Carcinoma (n = 1/12). MPE cancer cells and a lung cancer cell line (NCI-H-2122) exhibit chromosomal abnormalities and 1p36 deletion (n = 3/3). Since miR-34a maps to the 1p36 deletion site, low miR-34a expression levels were detected in these cells. The colony forming efficiency of CD44hi cells, characteristic property of CSC, can be inhibited by mir-34a replacement in these samples. In addition the highly tumorigenic CD44hi cells are enriched for cells in the G2 phase of cell cycle.


Health & Place | 2016

Heat Death Associations with the built environment, social vulnerability and their interactions with rising temperature

David Eisenman; Holly Wilhalme; Chi Hong Tseng; Mikhail Chester; Paul English; Stephanie Pincetl; Andrew Fraser; Sitaram Vangala; Satvinder K. Dhaliwal

In an extreme heat event, people can go to air-conditioned public facilities if residential air-conditioning is not available. Residences that heat slowly may also mitigate health effects, particularly in neighborhoods with social vulnerability. We explored the contributions of social vulnerability and these infrastructures to heat mortality in Maricopa County and whether these relationships are sensitive to temperature. Using Poisson regression modeling with heat-related mortality as the outcome, we assessed the interaction of increasing temperature with social vulnerability, access to publicly available air conditioned space, home air conditioning and the thermal properties of residences. As temperatures increase, mortality from heat-related illness increases less in census tracts with more publicly accessible cooled spaces. Mortality from all internal causes of death did not have this association. Building thermal protection was not associated with mortality. Social vulnerability was still associated with mortality after adjusting for the infrastructure variables. To reduce heat-related mortality, the use of public cooled spaces might be expanded to target the most vulnerable.


Epidemiology and Infection | 2016

Patient-level analysis of incident vancomycin-resistant enterococci colonization and antibiotic days of therapy

James A. McKinnell; Danielle Kunz; Stephen A. Moser; Sitaram Vangala; Chi-Hong Tseng; Martin F. Shapiro; Loren G. Miller

Vancomycin-resistant enterococci (VRE) infections are a public health threat associated with increased patient mortality and healthcare costs. Antibiotic usage, particularly cephalosporins, has been associated with VRE colonization and VRE bloodstream infections (VRE BSI). We examined the relationship between antimicrobial usage and incident VRE colonization at the individual patient level. Prospective, weekly surveillance was undertaken for incident VRE colonization defined by negative admission but positive surveillance swab in a medical intensive care unit over a 17-month period. Antimicrobial exposure was quantified as days of therapy (DOT)/1000 patient-days. Multiple logistic regression was used to analyse incident VRE colonization and antibiotic DOT, controlling for demographic and clinical covariates. Ninety-six percent (1398/1454) of admissions were swabbed within 24 h of intensive care unit (ICU) arrival and of the 380 patients in the ICU long enough for weekly surveillance, 83 (22%) developed incident VRE colonization. Incident colonization was associated in bivariate analysis with male gender, more previous hospital admissions, longer previous hospital stay, and use of cefepime/ceftazidime, fluconazole, azithromycin, and metronidazole (P < 0·05). After controlling for demographic and clinical covariates, metronidazole was the only antibiotic independently associated with incident VRE colonization (odds ratio 2·0, 95% confidence interval 1·2-3·3, P < 0·009). Our findings suggest that risk of incident VRE colonization differs between individual antibiotic agents and support the possibility that antimicrobial stewardship may impact VRE colonization and infection.


Health Promotion Practice | 2016

Testing an Adapted Modified Delphi Method: Synthesizing Multiple Stakeholder Ratings of Health Care Service Effectiveness

Anne L. Escaron; Rosy Chang Weir; Petra Stanton; Sitaram Vangala; Tristan Grogan; Robin Clarke

Background. The Affordable Care Act incentivizes health systems for better meeting patient needs, but often guidance about patient preferences for particular health services is limited. All too often vulnerable patient populations are excluded from these decision-making settings. A community-based participatory approach harnesses the in-depth knowledge of those experiencing barriers to health care. Method. We made three modifications to the RAND-UCLA appropriateness method, a modified Delphi approach, involving patients, adding an advisory council group to characterize existing knowledge in this little studied area, and using effectiveness rather than “appropriateness” as the basis for rating. As a proof of concept, we tested this method by examining the broadly delivered but understudied nonmedical services that community health centers provide. Results. This method created discrete, new knowledge about these services by defining 6 categories and 112 unique services and by prioritizing among these services based on effectiveness using a 9-point scale. Consistent with the appropriateness method, we found statistical convergence of ratings among the panelists. Discussion. Challenges include time commitment and adherence to a clear definition of effectiveness of services. This diverse stakeholder engagement method efficiently addresses gaps in knowledge about the effectiveness of health care services to inform population health management.


Ethnicity & Disease | 2016

The Healthy Community Neighborhood Initiative: Rationale and Design

Arleen F. Brown; D'Ann M. Morris; Katherine L. Kahn; Ibrahima C. Sankaré; Keyonna M. King; Roberto Vargas; Aziza Lucas-Wright; Loretta Jones; Astrea Flowers; Felica Jones; Rachelle Bross; Dennishia Banner; Homero E. del Pino; Orwilda L. Pitts; Lujia Zhang; Courtney Porter; Sigrid K. Madrigal; Stefanie D. Vassar; Sitaram Vangala; Li-Jung Liang; Arturo B. Martinez; Keith C. Norris

OBJECTIVE To describe the design and rationale of the Healthy Community Neighborhood Initiative (HCNI), a multi-component study to understand and document health risk and resources in a low-income and minority community. DESIGN A community-partnered participatory research project. SETTING A low-income, biethnic African American and Latino neighborhood in South Los Angeles. PARTICIPANTS Adult community residents aged >18 years. MAIN OUTCOME MEASURES Household survey and clinical data collection; neighborhood characteristics; neighborhood observations; and community resources asset mapping. RESULTS We enrolled 206 participants (90% of those eligible), of whom 205 completed the household interview and examination, and 199 provided laboratory samples. Among enrollees, 82 (40%) were aged >50 years and participated in functional status measurement. We completed neighborhood observations on 93 street segments; an average of 2.2 (SD=1.6) study participants resided on each street segment observed. The community asset map identified 290 resources summarized in a Community Resource Guide given to all participants. CONCLUSIONS The HCNI community-academic partnership has built a framework to assess and document the individual, social, and community factors that may influence clinical and social outcomes in a community at high-risk for preventable chronic disease. Our project suggests that a community collaborative can use culturally and scientifically sound strategies to identify community-centered health and social needs. Additional work is needed to understand strategies for developing and implementing interventions to mitigate these disparities.


Human Immunology | 2018

T cell dysfunction and patient age are associated with poor outcomes after mechanical circulatory support device implantation

Joanna Schaenman; Maura Rossetti; Yael Korin; Tiffany Sidwell; V. Groysberg; Emily Liang; Sitaram Vangala; Nicholas Wisniewski; E. Chang; M. Bakir; Galyna Bondar; Martin Cadeiras; M. Kwon; Elaine F. Reed; Mario C. Deng

Immunologic impairment may contribute to poor outcomes after implantation of mechanical circulatory support device (MCSD), with infection often as a terminal event. The study of immune dysfunction is of special relevance given the growing numbers of older patients with heart disease. The aim of the study was to define which immunologic characteristics are associated with development of adverse clinical outcomes after MCSD implantation. We isolated peripheral blood mononuclear cells (PBMC) from patients pre- and up to 20 days post-MCSD implantation and analyzed them by multiparameter flow cytometry for T cell dysfunction, including terminal differentiation, exhaustion, and senescence. We used MELD-XI and SOFA scores measured at each time point as surrogate markers of clinical outcome. Older patients demonstrated increased frequencies of terminally differentiated T cells as well as NKT cells. Increased frequency of terminally differentiated and immune senescent T cells were associated with worse clinical outcome as measured by MELD-XI and SOFA scores, and with progression to infection and death. In conclusion, our data suggest that T cell dysfunction, independently from age, is associated with poor outcomes after MCSD implantation, providing a potential immunologic mechanism behind patient vulnerability to multiorgan dysfunction and death. This noninvasive approach to PBMC evaluation holds promise for candidate evaluation and patient monitoring.


Cancer immunology research | 2018

Treatment-Related Adverse Events Predict Improved Clinical Outcome in NSCLC Patients on KEYNOTE-001 at a Single Center

Aaron Lisberg; D. Andrew Tucker; Jonathan W. Goldman; Brian R. Wolf; James M. Carroll; Ariana R. Hardy; Karolyn Morris; Paulina J Linares; Carlos R. Adame; Marshall L. Spiegel; Courtney Wells; Jordan R. McKenzie; Blanca A. Ledezma; Melody Mendenhall; Phillip A. Abarca; Krikor Bornazyan; Jaime Hunt; Nima Moghadam; Natalie Chong; Danielle Nameth; Caitlin Marx; John Madrigal; Sitaram Vangala; Narek Shaverdian; David Elashoff; Edward B. Garon

A retrospective analysis of non–small cell lung carcinoma patients treated with pembrolizumab found that treatment-related adverse events predicted improved clinical outcome. This observation could identify the patients most likely to benefit from anti–PD-1 therapy. We retrospectively analyzed non–small cell lung cancer (NSCLC) patients from a single center treated with pembrolizumab on the KEYNOTE-001 trial and evaluated the association between treatment-related adverse events (trAEs) and clinical outcomes. Investigators reported AEs on trial and graded them according to Common Terminology Criteria for Adverse Events v4.0, labeling them as unlikely, possibly, or probably treatment-related. AEs labeled as possibly/probably related were considered trAEs for this analysis. The relationship between the incidence of a trAE and clinical outcomes was evaluated. Ninety-seven NSCLC patients treated on KEYNOTE-001 at the University of California, Los Angeles were evaluated. Ten percent (85/826) of AEs were trAEs, occurring in 40% (39/97) of patients. The most frequent trAEs were rash (21% patients), fatigue (6% patients), and hypothyroidism (6% patients). The 39 patients that experienced a trAE had increased objective response rate (ORR, 38.5%), progression-free survival (PFS: median, 248 days), and overall survival (OS: median, 493 days), compared with the 58 patients that did not (ORR: 8.9%, PFS: median 60 days, OS: median 144.5 days). The observed association between trAEs and improved clinical outcome persisted when using Cox proportional hazards regression models to assess the confounding effect of covariates and mitigate guarantee-time bias. The association also remained when data were substratified by grade, degree of association, and treatment-related select AE designation. This single-center analysis revealed that trAEs predicted for improved clinical outcome with pembrolizumab, and when controlling for guarantee-time bias and plausible confounders, this association remained. This observed relationship adds to our understanding of anti–PD-1 therapy and could aid clinicians in identifying patients most likely to benefit from therapy. Cancer Immunol Res; 6(3); 288–94. ©2018 AACR.

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David Elashoff

University of California

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Chi-Hong Tseng

University of California

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James A. McKinnell

Los Angeles Biomedical Research Institute

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Alison Goate

Icahn School of Medicine at Mount Sinai

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Daniel S. Marcus

Washington University in St. Louis

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David Wharton

University of California

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Edmond Teng

University of California

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