Dipankar Bandyopadhyay
Virginia Commonwealth University
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Publication
Featured researches published by Dipankar Bandyopadhyay.
Hypertension | 2012
Brent M. Egan; Dipankar Bandyopadhyay; Stephanie R. Shaftman; C. Shaun Wagner; Yumin Zhao; Kristina Yu-Isenberg
Initial antihypertensive therapy with single-pill combinations produced more rapid blood pressure control than initial monotherapy in clinical trials. Other studies reported better cardiovascular outcomes in patients achieving lower blood pressure during the first treatment year. We assessed the effectiveness of initial antihypertensive monotherapy, free combinations, and single-pill combinations in controlling untreated, uncontrolled hypertensives during their first treatment year. Electronic record data were obtained from 180 practice sites; 106 621 hypertensive patients seen from January 2004 to June 2009 had uncontrolled blood pressure, were untreated for ≥6 months before therapy, and had ≥1 one-year follow-up blood pressure data. Control was determined by the first follow-up visit with blood pressure <140/<90 mm Hg for patients without diabetes mellitus or chronic kidney disease and <130/<80 mm Hg for patients with either or both conditions. Multivariable hazards regression ratios (HRs) and 95% CIs for time to control were calculated, adjusting for age, sex, baseline blood pressure, body mass index, diabetes mellitus, chronic kidney disease, cardiovascular disease, initial therapy, final blood pressure medication number, and therapeutic inertia. Patients on initial single-pill combinations (N=9194) were more likely to have stage 2 hypertension than those on free combinations (N=18 328) or monotherapy (N=79 099; all P<0.001). Initial therapy with single-pill combinations (HR, 1.53 [95% CI, 1.47–1.58]) provided better hypertension control in the first year than free combinations (HR, 1.34; [95% CI, 1.31–1.37]) or monotherapy (reference) with benefits in black and white patients. Greater use of single-pill combinations as initial therapy may improve hypertension control and cardiovascular outcomes in the first treatment year.
Criminal Justice Policy Review | 2010
Elizabeth J. Letourneau; Jill S. Levenson; Dipankar Bandyopadhyay; Debajyoti Sinha; Kevin S. Armstrong
Some sex offender registration and notification (SORN) policies subject all registered sex offenders to Internet notification. The present study examined the effects of one such broad notification policy on sex crime recidivism. Secondary data were analyzed for a sample of 6,064 male offenders convicted of at least one sex crime between 1990 and 2004. Across a mean follow-up of 8.4 years, 490 (8%) offenders had new sex crime charges and 299 (5%) offenders had new sex crime convictions. Cox’s relative risks and competing risks models estimated the influence of registration status on risk of sexual recidivism while controlling for time at risk. Registration status did not predict recidivism in any model. These results cast doubt on the effectiveness of broad SORN policies in preventing repeat sexual assault. Policy implications, particularly with respect to the federal Adam Walsh Child Protection and Safety Act, which requires broad notification, are discussed.
Diabetes Research and Clinical Practice | 2009
Hon K. Yuen; Bethany J. Wolf; Dipankar Bandyopadhyay; Kathryn M. Magruder; Carlos F. Salinas; Steven D. London
The purpose of this study was to determine levels of oral health knowledge and factors associated with adequate oral health knowledge in adults with diabetes. A convenience sample of 253 adult US residents with diabetes completed an oral health survey to assess their knowledge. Results showed that only 47% of the participants answered five or more (out of a maximum of seven) oral health knowledge items related to diabetes correctly. Participants who received oral health information related to diabetes have 2.9 times the odds of possessing adequate oral health knowledge (i.e., answered five or more items correctly) compared to participants who did not received that information controlling for education and race (OR=2.86, 95% CI 1.31-6.24, P=0.008). Given that oral health information provided by health professionals (dental and/or medical) contributes to improve oral health knowledge among adults with diabetes, health professionals should take the opportunity to educate patients with diabetes about the oral manifestations (e.g., dry mouth) and complications (e.g., periodontitis and oral candidiasis) of diabetes and to promote proper oral health behaviors.
Journal of Clinical Periodontology | 2010
Dipankar Bandyopadhyay; Nicole M. Marlow; Jyotika K. Fernandes; Renata S. Leite
AIM To evaluate associations between glycaemic control and periodontitis progression among Gullah African Americans with type-2 diabetes mellitus (T2DM). MATERIALS AND METHODS From an ongoing clinical trial among T2DM Gullah, we extracted a cohort previously in a cross-sectional study (N=88). Time from baseline (previous study) to follow-up (trial enrollment, before treatment interventions) ranged 1.93-4.08 years [mean=2.99, standard deviation (SD)=0.36]. We evaluated tooth site-level periodontitis progression [clinical attachment loss (CAL) worsening of > or =2 mm, periodontal probing depth (PPD) increases of > or =2 mm and bleeding on probing (BOP) from none to present] by glycaemic control status (well-controlled=HbA(1c)<7%, poorly-controlled=HbA(1c)> or =7%) using multivariable generalized estimating equations logistic regression, nesting tooth sites/person. RESULTS Poorly-controlled T2DM (68.18%) was more prevalent than well-controlled T2DM (31.82%). Proportions of tooth sites/person with CAL progression between baseline and follow-up ranged 0.00-0.59 (mean=0.12, SD=0.12), while PPD and BOP progression ranged 0.00-0.44 (mean=0.09, SD=0.11) and 0.00-0.96 (mean=0.24, SD=0.18), respectively. Site-level PPD at baseline was a significant effect modifier of associations between poorly-controlled T2DM and site-level CAL and PPD progression [adjusted odds ratios (OR) according to poorly-controlled T2DM among PPD at baseline=3, 5 and 7 mm, respectively: CAL progression=1.93, 2.64, and 3.62, PPD progression=1.98, 2.76, and 3.84; p<0.05 for all]. Odds of site-level BOP progression were increased (OR=1.24) for poorly-controlled T2DM, yet the results were not significant (p=0.32). CONCLUSIONS These findings from a distinct, homogenous population further support the clinical relevance of identifying patients with poor glycaemic control and periodontitis, particularly among those with disparities for both diseases.
Biometrics | 2011
Victor H. Lachos; Dipankar Bandyopadhyay; Dipak K. Dey
HIV RNA viral load measures are often subjected to some upper and lower detection limits depending on the quantification assays. Hence, the responses are either left or right censored. Linear (and nonlinear) mixed-effects models (with modifications to accommodate censoring) are routinely used to analyze this type of data and are based on normality assumptions for the random terms. However, those analyses might not provide robust inference when the normality assumptions are questionable. In this article, we develop a Bayesian framework for censored linear (and nonlinear) models replacing the Gaussian assumptions for the random terms with normal/independent (NI) distributions. The NI is an attractive class of symmetric heavy-tailed densities that includes the normal, Students-t, slash, and the contaminated normal distributions as special cases. The marginal likelihood is tractable (using approximations for nonlinear models) and can be used to develop Bayesian case-deletion influence diagnostics based on the Kullback-Leibler divergence. The newly developed procedures are illustrated with two HIV AIDS studies on viral loads that were initially analyzed using normal (censored) mixed-effects models, as well as simulations.
Criminal Justice and Behavior | 2010
Elizabeth J. Letourneau; Jill S. Levenson; Dipankar Bandyopadhyay; Kevin S. Armstrong; Debajyoti Sinha
This study examined whether South Carolina’s sex offender registration and notification (SORN) policy was associated with a general deterrent effect on adult sex crimes. Using adult arrest data from 1990 through 2005, trend analyses modeled the intervention effects of 1995 (the year South Carolina’s SORN policy was initially implemented) and 1999 (the year the policy was revised to include online registration). Results supported a significant deterrent effect for the 1995 intervention year, with an approximately 11% reduction in first-time sex crime arrests in the post-SORN period (1995-2005) relative to the pre-SORN period (1990-1994). This decline equated to averting approximately three new sex crime arrests per month. Comparison analyses with serious nonsex offenses against persons (assault and robbery) failed to identify similar effects, suggesting that the 1995 effect is attributable to sex offense—specific legislation. Findings are compared with the existing literature on general deterrent effects of SORN and discussed in the context of research examining other effects of SORN.
Criminal Justice Policy Review | 2009
Elizabeth J. Letourneau; Dipankar Bandyopadhyay; Debajyoti Sinha; Kevin S. Armstrong
This study examines the influence of South Carolinas sex offender registration policy on juvenile offender recidivism risk. Juvenile male sexual offender (N = 1,275) risk of recidivism was examined with an average 9-year follow-up. Survival analysis was used to examine the influence of covariates, including the primary time-dependent covariate registration status at time, on risk of new sexual offense charges and adjudications. A competing risks model was used to explain the effects of covariates on different types of recidivism events (sexual, assault, and other). Registration status at time had a significant effect on risk of new “other” offense charges and a marginal (p < .10) effect on risk of sexual offense charges (survival analysis) but no statistical evidence of affecting risk of new adjudications. Results suggest a surveillance effect leading to unnecessary charges for registered (vs. nonregistered) youth. State and national policy implications are discussed.
Sexual Abuse: A Journal of Research and Treatment | 2009
Elizabeth J. Letourneau; Dipankar Bandyopadhyay; Debajyoti Sinha; Kevin S. Armstrong
This study examines effects of sex offender registration policies on juvenile judicial decision making. Prosecutor decisions and disposition outcomes are examined across a 15-year period. Results indicate that prosecutors are significantly less likely to move forward on both serious sexual and assault offense charges after registration implementation, with the estimated effect nearly twice as large for sexual offenses. There also is increased likelihood of guilty findings for sexual and assault offenses over time. As new policies legislate harsher consequences for juvenile offenses, prosecutors become less likely to move forward on sexual and assault charges. This effect is especially strong for juvenile sexual offenders, who face reforms targeting both violent and sexual crimes. Results suggest that state and national policies requiring long-term public registration of juveniles might unintentionally decrease the likelihood of prosecution. If replicated, the results indicate a need to reform registration policies as applied to juveniles.
Criminal Justice and Behavior | 2010
Elizabeth J. Letourneau; Dipankar Bandyopadhyay; Kevin S. Armstrong; Debajyoti Sinha
This study examined whether South Carolina’s sex offender registration and notification (SORN) policy was associated with a general deterrent effect on juvenile sex crimes. Using juvenile justice data from 1991 through 2004, trend analyses modeled the intervention effects of 1995 (the year South Carolina’s SORN policy was initially implemented) and 1999 (the year the policy was revised to include online registration). Initial results suggested a significant deterrent effect of SORN on first-time juvenile sex crimes. However, comparison analyses with nonsex offenses identified a similar effect on first-time robbery crimes. Follow-up analyses indicated that the apparent declines identified for first-time sex and robbery offenses were due to another legislative change, also enacted in 1995, that moved the prosecution of 16-year-old defendants from juvenile to adult court. When these cases were included in the database, follow-up analyses indicated no significant effect for the 1995 intervention year. Thus, South Carolina’s SORN policy was not associated with a general deterrent effect on juvenile sex crimes. Specific policy changes are suggested regarding the application of registration and notification requirements to juveniles.
Oral Oncology | 2009
Angela C. Chi; Kathryn M. Appleton; Joel B. Henriod; Joe W. Krayer; Nicole M. Marlow; Dipankar Bandyopadhyay; Ryan C. Sigmon; David T. Kurtz
UNLABELLED Polyaromatic hydrocarbons, including benzo[a]pyrene (BP), are major tobacco carcinogens. Their carcinogenic effects require metabolic activation by cytochrome p450 (CYP) enzymes. Relative CYP isoform expression is related to tissue-specific tobacco-related squamous cell carcinoma (SCC) susceptibility. There have been conflicting reports regarding relative CYP1A1 and CYP1B1 oral expression, and information regarding CYP1B1 expression in oral tissues is limited. To quantify BP- and tobacco-induced CYP1A1 and CYP1B1 expression in oral SCC cells and oral mucosa. STUDY DESIGN Real-time qPCR was performed to measure (1) BP-induced CYP1A1 and CYP1B1 mRNA expression in seven oral/other head and neck SCC cell lines (2) CYP1A1 and CYP1B1 mRNA expression in gingiva from 22 smokers and 24 nonsmokers. SCC lines exhibited either similar induction of both isoforms or preferential CYP1A1 induction (CYP1A1-to-CYP1B1 ratios 0.8-4.3). In contrast, gingival tissues from smokers exhibited preferential CYP1B1 induction. Marked interindividual variation in CYP1A1 and CYP1B1 expression was observed among smokers. In vitro conditions may not account for factors that modulate expression in vivo. Interindividual variation in inducible CYP1A1 and CYP1B1 expression may account in part for variation in tobacco-related oral SCC risk.