Publications

2014

Woolery, Kamisha T, Mitchel S Hoffman, Joshua Kraft, Santo Nicosia V, Ambuj Kumar, and Patricia A Kruk. (2014) 2014. “Urinary Interleukin-1β Levels Among Gynecological Patients.”. Journal of Ovarian Research 7: 104. https://doi.org/10.1186/s13048-014-0104-4.

BACKGROUND: Early detection of epithelial ovarian cancer (OC) is necessary to overcome the high mortality rate of late stage diagnosis; and, examining the molecular changes that occur at early disease onset may provide new strategies for OC detection. Since the deregulation of inflammatory mediators can contribute to OC development, the purpose of this pilot study was to determine whether elevated urinary levels of Interleukin-1beta (IL-1 beta) are associated with OC and associated clinical parameters.

METHODS: Urinary and serum levels of IL-1 beta were analyzed by ELISA from a patient cohort consisting of healthy women (N = 10), women with ovarian benign disease (N = 23), women with OC (N = 32), women with other benign gynecological conditions (N = 22), and women with other gynecological cancers (N = 6).

RESULTS: Average urinary IL-1 beta levels tended to be elevated in ovarian benign (1.26 pg/ml) and OC (1.57 pg/ml) patient samples compared to healthy individuals (0.36 pg/ml). Among patients with benign disease, urinary IL-1β levels were statistically higher in patients with benign inflammatory gynecologic disease compared to patients with non-inflammatory benign disease. Interestingly, urinary IL-1 beta levels tended to be 3-6x greater in patients with benign ovarian disease or OC as well as with a concomitant family history of ovarian and/or breast cancer compared to similar patients without a family history of ovarian and/or breast cancer. Lastly, there was a pattern of increased urinary IL-1 beta with increasing body mass index (BMI); patients with a normal BMI averaged urinary IL-1 beta levels of 0.92 pg/ml, overweight BMI averaged urinary IL-1 beta levels of 1.72 pg/ml, and obese BMI averaged urinary IL-1 beta levels of 5.26 pg/ml.

CONCLUSIONS: This pilot study revealed that urinary levels of IL-1 beta are elevated in patients with epithelial OC supporting the thought that inflammation might be associated with cancer progression. Consequently, further studies of urinary IL-1 beta and the identification of an inflammatory profile specific to OC development may be beneficial to reduce the mortality associated with this disease.

Reljic, Tea, Helen Mahony, Benjamin Djulbegovic, Jeff Etchason, Hannah Paxton, Michelle Flores, and Ambuj Kumar. (2014) 2014. “Value of Repeat Head Computed Tomography After Traumatic Brain Injury: Systematic Review and Meta-Analysis.”. Journal of Neurotrauma 31 (1): 78-98. https://doi.org/10.1089/neu.2013.2873.

Diagnosis and management of traumatic brain injury (TBI) is crucial to improve patient outcomes. While initial head computed tomography (CT) scan is the optimum tool for quick and accurate detection of intracranial hemorrhage, the guidelines on use of repeat CT differ among institutions. Three systematic reviews have been conducted on a similar topic; none have performed a comprehensive meta-analysis of all studies. Search of Medline, the Cochrane Library database, and Clinicaltrials.gov , and a hand search of conference abstracts and references for all completed studies reporting data on change in management following repeat CT was conducted. Two authors reviewed all studies and extracted data using a standardized form. A proportional meta-analysis was conducted using the random-effects model for outcomes related to any change in management following repeat CT. Any change in management included intracranial intervention, change in intracranial pressure monitoring, and/or administration of drug therapy. Search results yielded 6982 references. In all, 41 studies enrolling 10,501 patients were included. Change in management following repeat CT was reported in 13 prospective and 28 retrospective studies and yielded a pooled proportion of 11.4% (95% confidence interval [CI] 5.9-18.4) and 9.6% (95% CI 6.5-13.2), respectively. In a subgroup analysis of mild TBI patients (Glasgow Coma Scale score 13 to 15), five prospective and nine retrospective studies reported on change in management following repeat CT with the pooled proportion across prospective studies at 2.3% (95% CI 0.3-6.3) and across retrospective studies at 3.9% (95% CI 2.3-5.7), respectively. The evidence suggests that repeat CT in patients with TBI results in a change in management for only a minority of patients. Better designed studies are needed to address the issue of the value of repeat CT in the management of TBI.

Koskan, Alexis, Lynne Klasko, Stacy N Davis, Clement K Gwede, Kristen J Wells, Ambuj Kumar, Natalia Lopez, and Cathy D Meade. (2014) 2014. “Use and Taxonomy of Social Media in Cancer-Related Research: A Systematic Review.”. American Journal of Public Health 104 (7): e20-37. https://doi.org/10.2105/AJPH.2014.301980.

Little is known about how social media are used in cancer care. We conducted a systematic review of the use and taxonomy of social media in cancer-related studies, in PubMed, Web of Knowledge, CINAHL, and Google Scholar. We located 1350 articles published through October 2013; 69 met study inclusion criteria. Early research (1996-2007) was predominantly descriptive studies of online forums. Later, researchers began analyzing blogs, videos shared on YouTube, and social networking sites. Most studies (n = 62) were descriptive, and only 7 reported intervention studies published since 2010. Future research should include more intervention studies to determine how social media can influence behavior, and more empirical research is needed on how social media may be used to reduce health disparities.

Kumar, Ambuj, Vidya Rajendran, Rao Sethumadhavan, and Rituraj Purohit. (2014) 2014. “Role of Centrosome in Regulating Immune Response.”. Current Drug Targets 15 (5): 558-63.

Centrosomes are the vital component of cell cycle progression pathway. Recent investigations have suggested their role in regulating the immune response system. Centrosome polarization delivers secretory granules to the immunological synapse (IS). The Cytotoxic T lymphocytes use a specific mechanism, controlled by centrosome delivery to the plasma membrane for delivering the secretory granules to the immunological synapse. Moreover, the polarization of centrioles to the immunological synapse directs secretion from cytolytic cells of innate as well as adaptive immune systems. Although the recent investigations have suggested their strong role in mediating the crucial events of immunological response, there are few discrepancies that are yet to be resolved. Furthermore, a clear picture of their molecular mechanism along with their cellular functions has not been reported. In this manuscript we have reviewed some important points that explain the importance of centrosomes in mediating the immunological signals and the delivery of lytic discharge from the cytotoxic and killer cells.

Kumar, Ambuj, Vidya Rajendran, Rao Sethumadhavan, Priyank Shukla, Shalinee Tiwari, and Rituraj Purohit. (2014) 2014. “Computational SNP Analysis: Current Approaches and Future Prospects.”. Cell Biochemistry and Biophysics 68 (2): 233-9. https://doi.org/10.1007/s12013-013-9705-6.

The computational approaches in determining disease-associated Non-synonymous single nucleotide polymorphisms (nsSNPs) have evolved very rapidly. Large number of deleterious and disease-associated nsSNP detection tools have been developed in last decade showing high prediction reliability. Despite of all these highly efficient tools, we still lack the accuracy level in determining the genotype-phenotype association of predicted nsSNPs. Furthermore, there are enormous questions that are yet to be computationally compiled before we might talk about the prediction accuracy. Earlier we have incorporated molecular dynamics simulation approaches to foster the accuracy level of computational nsSNP analysis roadmap, which further helped us to determine the changes in the protein phenotype associated with the computationally predicted disease-associated mutation. Here we have discussed on the present scenario of computational nsSNP characterization technique and some of the questions that are crucial for the proper understanding of pathogenicity level for any disease associated mutations.

Djulbegovic, Benjamin, Shira Elqayam, Tea Reljic, Iztok Hozo, Branko Miladinovic, Athanasios Tsalatsanis, Ambuj Kumar, Jason Beckstead, Stephanie Taylor, and Janice Cannon-Bowers. (2014) 2014. “How Do Physicians Decide to Treat: An Empirical Evaluation of the Threshold Model.”. BMC Medical Informatics and Decision Making 14: 47. https://doi.org/10.1186/1472-6947-14-47.

BACKGROUND: According to the threshold model, when faced with a decision under diagnostic uncertainty, physicians should administer treatment if the probability of disease is above a specified threshold and withhold treatment otherwise. The objectives of the present study are to a) evaluate if physicians act according to a threshold model, b) examine which of the existing threshold models [expected utility theory model (EUT), regret-based threshold model, or dual-processing theory] explains the physicians' decision-making best.

METHODS: A survey employing realistic clinical treatment vignettes for patients with pulmonary embolism and acute myeloid leukemia was administered to forty-one practicing physicians across different medical specialties. Participants were randomly assigned to the order of presentation of the case vignettes and re-randomized to the order of "high" versus "low" threshold case. The main outcome measure was the proportion of physicians who would or would not prescribe treatment in relation to perceived changes in threshold probability.

RESULTS: Fewer physicians choose to treat as the benefit/harms ratio decreased (i.e. the threshold increased) and more physicians administered treatment as the benefit/harms ratio increased (and the threshold decreased). When compared to the actual treatment recommendations, we found that the regret model was marginally superior to the EUT model [Odds ratio (OR) = 1.49; 95% confidence interval (CI) 1.00 to 2.23; p = 0.056]. The dual-processing model was statistically significantly superior to both EUT model [OR = 1.75, 95% CI 1.67 to 4.08; p < 0.001] and regret model [OR = 2.61, 95% CI 1.11 to 2.77; p = 0.018].

CONCLUSIONS: We provide the first empirical evidence that physicians' decision-making can be explained by the threshold model. Of the threshold models tested, the dual-processing theory of decision-making provides the best explanation for the observed empirical results.

Kharfan-Dabaja, Mohamed, Rahul Mhaskar, Tea Reljic, Joseph Pidala, Janelle B Perkins, Benjamin Djulbegovic, and Ambuj Kumar. (2014) 2014. “Mycophenolate Mofetil versus Methotrexate for Prevention of Graft-versus-Host Disease in People Receiving Allogeneic Hematopoietic Stem Cell Transplantation.”. The Cochrane Database of Systematic Reviews 2014 (7): CD010280. https://doi.org/10.1002/14651858.CD010280.pub2.

BACKGROUND: Allogeneic hematopoietic stem cell transplantation (allo-HCT) is associated with improved outcomes for people with various hematologic diseases; however, the morbidity and mortality resulting from acute and subsequently chronic graft-versus-host disease (GVHD) pose a serious challenge to wider applicability of allo-HCT. Intravenous methotrexate in combination with a calcineurin inhibitor, cyclosporine or tacrolimus, is a widely used regimen for the prophylaxis of acute GVHD, but the administration of methotrexate is associated with a number of adverse events. Mycophenolate mofetil, in combination with a calcineurin inhibitor, has been used extensively in people undergoing allo-HCT. Conflicting results regarding various clinical outcomes following allo-HCT have been observed when comparing mycophenolate mofetil-based regimens against methotrexate-based regimens for acute GVHD prophylaxis.

PRIMARY OBJECTIVE: to assess the effect of mycophenolate mofetil versus methotrexate for prevention of acute GVHD in people undergoing allo-HCT.

SECONDARY OBJECTIVES: to evaluate the effect of mycophenolate mofetil versus methotrexate for overall survival, prevention of chronic GVHD, incidence of relapse, treatment-related harms, nonrelapse mortality, and quality of life.

SEARCH METHODS: We searched Cochrane Central Register of Controlled Trials (CENTRAL) and MEDLINE from inception to March 2014. We handsearched conference abstracts from the last two meetings (2011 and 2012) of relevant societies in the field. We searched ClinicalTrials.gov, Novartis clinical trials database (www.novctrd.com), Roche clinical trial protocol registry (www.roche-trials.com), Australian New Zealand Clinical Trials Registry (ANZCTR), and the metaRegister of Controlled Trials for ongoing trials.

SELECTION CRITERIA: Two review authors independently reviewed all titles/abstracts and selected full-text articles for inclusion. We included all references that reported results of randomized controlled trials (RCTs) of mycophenolate mofetil versus methotrexate for the prophylaxis of GVHD among people undergoing allo-HCT in this review.

DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data on outcomes from all studies and compared prior to data entry and analysis. We expressed results as risk ratios (RR) and 95% confidence intervals (CI) for dichotomous outcomes and hazard ratios (HR) and 95% CIs for time-to-event outcomes. We pooled the individual study effects using the random-effects model. Estimates lower than one indicate that mycophenolate mofetil was favored over methotrexate.

MAIN RESULTS: We included three trials enrolling 177 participants (174 participants analyzed). All participants in the trials by Keihl et al. and Bolwell et al. received cyclosporine while all participants enrolled in the trial by Perkins et al. received tacrolimus. However, the results did not differ by the type of calcineurin inhibitor employed (cyclosporine versus tacrolimus). There was no evidence for a difference between mycophenolate mofetil versus methotrexate for the outcomes of incidence of acute GVHD (RR 1.25; 95% CI 0.75 to 2.09; P value = 0.39, very low quality evidence), overall survival (HR 0.73; 95% CI 0.45 to 1.17; P value = 0.19, low-quality evidence), median days to neutrophil engraftment (HR 0.77; 95% CI 0.51 to 1.17; P value = 0.23, low-quality evidence), incidence of relapse (RR 0.84; 95% CI 0.52 to 1.38; P value = 0.50, low-quality evidence), non-relapse mortality (RR 1.21; 95% CI 0.62 to 2.36; P value = 0.57, low-quality evidence), and incidence of chronic GVHD (RR 0.92; 95% CI 0.65 to 1.30; P value = 0.62, low-quality evidence). There was low-quality evidence that mycophenolate mofetil compared with methotrexate improved platelet engraftment period (HR 0.87; 95% CI 0.81 to 0.93; P value < 0.0001, low-quality evidence). There was low-quality evidence that mycophenolate mofetil compared with methotrexate resulted in decreased incidence of severe mucositis (RR 0.48; 95% CI 0.32 to 0.73; P value = 0.0006, low-quality evidence), use of parenteral nutrition (RR 0.48; 95% CI 0.26 to 0.91; P value = 0.02, low-quality evidence), and medication for pain control (RR 0.76; 95% CI 0.63 to 0.91; P value = 0.002, low-quality evidence). Overall heterogeneity was not detected in the analysis except for the outcome of neutrophil engraftment. None of the included studies reported any outcomes related to quality of life. Overall quality of evidence was low.

AUTHORS' CONCLUSIONS: The use of mycophenolate mofetil compared with methotrexate for primary prevention of GVHD seems to be associated with a more favorable toxicity profile, without an apparent compromise on disease relapse, transplant-associated mortality, or overall survival. The effects on incidence of GVHD between people receiving mycophenolate mofetil compared with people receiving methotrexate were uncertain. There is a need for additional high-quality RCTs to determine the optimal GVHD prevention strategy. Future studies should take into account a comprehensive view of clinical benefit, including measures of morbidity, symptom burden, and healthcare resource utilization associated with interventions.

Djulbegovic, Benjamin, Jason W Beckstead, Shira Elqayam, Tea Reljic, Iztok Hozo, Ambuj Kumar, Janis Cannon-Bowers, et al. (2014) 2014. “Evaluation of Physicians’ Cognitive Styles.”. Medical Decision Making : An International Journal of the Society for Medical Decision Making 34 (5): 627-37. https://doi.org/10.1177/0272989X14525855.

BACKGROUND: Patient outcomes critically depend on accuracy of physicians' judgment, yet little is known about individual differences in cognitive styles that underlie physicians' judgments. The objective of this study was to assess physicians' individual differences in cognitive styles relative to age, experience, and degree and type of training.

METHODS: Physicians at different levels of training and career completed a web-based survey of 6 scales measuring individual differences in cognitive styles (maximizing v. satisficing, analytical v. intuitive reasoning, need for cognition, intolerance toward ambiguity, objectivism, and cognitive reflection). We measured psychometric properties (Cronbach's α) of scales; relationship of age, experience, degree, and type of training; responses to scales; and accuracy on conditional inference task.

RESULTS: The study included 165 trainees and 56 attending physicians (median age 31 years; range 25-69 years). All 6 constructs showed acceptable psychometric properties. Surprisingly, we found significant negative correlation between age and satisficing (r = -0.239; P = 0.017). Maximizing (willingness to engage in alternative search strategy) also decreased with age (r = -0.220; P = 0.047). Number of incorrect inferences negatively correlated with satisficing (r = -0.246; P = 0.014). Disposition to suppress intuitive responses was associated with correct responses on 3 of 4 inferential tasks. Trainees showed a tendency to engage in analytical thinking (r = 0.265; P = 0.025), while attendings displayed inclination toward intuitive-experiential thinking (r = 0.427; P = 0.046). However, trainees performed worse on conditional inference task.

CONCLUSION: Physicians capable of suppressing an immediate intuitive response to questions and those scoring higher on rational thinking made fewer inferential mistakes. We found a negative correlation between age and maximizing: Physicians who were more advanced in their careers were less willing to spend time and effort in an exhaustive search for solutions. However, they appeared to have maintained their "mindware" for effective problem solving.

Abu-Dalle, Iman, Tea Reljic, Taiga Nishihori, Ahmad Antar, Ali Bazarbachi, Benjamin Djulbegovic, Ambuj Kumar, and Mohamed A Kharfan-Dabaja. (2014) 2014. “Extracorporeal Photopheresis in Steroid-Refractory Acute or Chronic Graft-versus-Host Disease: Results of a Systematic Review of Prospective Studies.”. Biology of Blood and Marrow Transplantation : Journal of the American Society for Blood and Marrow Transplantation 20 (11): 1677-86. https://doi.org/10.1016/j.bbmt.2014.05.017.

Acute and chronic graft-versus-host disease (GVHD) remain major obstacles for successful allogeneic hematopoietic cell transplantation. Extracorporeal photopheresis (ECP) modulates immune cells, such as alloreactive T cells and dendritic cells, and improves GVHD target organ function(s) in steroid-refractory GVHD patients. We performed a systematic review to evaluate the totality of evidence regarding the efficacy of ECP for treatment of acute and chronic steroid-refractory or steroid-dependent GVHD. Nine studies, including 1 randomized controlled trial, met inclusion criteria, with a total of 323 subjects. In pooled analyses, overall response rates (ORR) were .69 (95% confidence interval [CI], .34 to .95) and .64 (95% CI, .47 to .79) for acute and chronic GVHD, respectively. In acute GVHD organ-specific responses, ECP resulted in the highest ORR for cutaneous, with .84 (95% CI, .75 to .92), followed by gastrointestinal with .65 (95% CI, .52 to .78). Similar response rates were seen in chronic GVHD involving the skin and gastrointestinal tract. Conversely, ORR for chronic GVHD involving the lungs was only .15 (95% CI, 0 to .5). In chronic GVHD, grades 3 to 4 adverse events were reported at .38 (95% CI, .06 to .78). ECP-related mortality rates were extremely low. Rates of immunosuppression discontinuation were .55 (95% CI, .40 to .70) and .23 (95% CI, .07 to .44) for acute and chronic GVHD, respectively. In summary, albeit limited by numbers of available studies, pooled analyses of prospective studies demonstrate encouraging responses after ECP treatment in acute and chronic GVHD after failing corticosteroids. Further research efforts are needed to improve organ-specific responses.