Publications
Department of Medicine faculty members published more than 3,600 peer-reviewed articles in 2024.
2016
2016
OBJECTIVE
Kidney dysfunction in obesity may be independent of and may precede the development of hypertension and/or diabetes mellitus. We aimed to examine if abdominal obesity is associated with early markers of CKD in a young healthy population and whether these associations differ by race and/or ethnicity.
METHODS
We analyzed data from the NHANES 1999-2010 for 6918 young adults ages 20-40 years. Abdominal obesity was defined by gender criteria of waist circumference. CKD markers included estimated glomerular filtration rate and albuminuria ≥30 mg/g. Race stratified analyses were done overall and in subgroups with normal blood pressures, normoglycemia and normal insulin sensitivity. Awareness of CKD was assessed in participants with albuminuria.
RESULTS
Abdominal obesity was present in over one-third of all young adults and was more prevalent among non-Hispanic blacks (45.4%) versus Mexican-Americans (40.6%) or non-Hispanic whites (37.4%) (P-value = 0.004). Mexican-American young adults with abdominal obesity had a higher odds of albuminuria even among those with normal blood pressure, normal glucose, and normal insulin sensitivity [adjusted odds ratio 4.5; 95% confidence interval (1.6-12.2), p = 0.004]. Less than 5% of young adults with albuminuria of all races and ethnicities had been told they had kidney disease.
CONCLUSION
Abdominal obesity in young adults, especially in Mexican-Americans, is independently associated with albuminuria even with normal blood pressures, normoglycemia and normal insulin levels. Greater awareness of CKD is needed to protect this young population from long-standing exposure to abdominal obesity and early progressive renal disease.
View on PubMed2016
2016
HIV-infected individuals have activated monocytes with an IFNα phenotype and elevated levels of circulating LPS. These individuals also have a risk of premature cardiovascular disease. The effect of activated monocyte exosomes (Exos) on endothelial cells is unknown. To determine whether Exos from immune-activated monocytes could alter endothelial cell expression and contribute to monocyte/macrophage transmigration and adhesion, we isolated Exos from monocytes stimulated with IFNα, LPS, or both (I/L). We show that monocyte Exos contain different inflammatory microRNA cargo depending on stimulation. When LPS Exos or I/L Exos were added to HUVECs, we found a significant increase in adhesion molecule ICAM-1, chemokine ligand (CCL)-2, and cytokine IL-6 mRNAs and proteins compared with cells treated with IFNα Exos or Exos derived from unstimulated monocytes. Inhibition of transcription factor NF-κB, a common inflammatory cytokine pathway, prevented induction of CCL2, IL6, and ICAM1 Inhibition of TLR4 resulted in differential blockage of the targets. Our results demonstrate for the first time that primary human monocyte Exos enter endothelial cells and cause dysfunction via the TLR4 and NF-κB pathways, which may contribute to heart disease in HIV infection and other diseases involving chronic immune activation.-Tang, N., Sun, B., Gupta, A., Rempel, H., Pulliam, L. Monocyte exosomes induce adhesion molecules and cytokines via activation of NF-κB in endothelial cells.
View on PubMed2016
OBJECTIVES
This study investigated clinical and electrophysiological findings in patients with incessant atrioventricular nodal reentrant tachycardia (AVNRT).
BACKGROUND
AVNRT is the most frequent cause of paroxysmal supraventricular tachycardia (SVT) and, rarely, incessant SVT. There are a few case reports describing incessant AVNRT.
METHODS
Among 342 patients treated using ablation for AVNRT, we identified 8 patients with incessant AVNRT (2.3%). We describe the clinical and electrophysiological features of patients with incessant AVNRT and compare them with those of patients with paroxysmal AVNRT (n = 334).
RESULTS
This study population consisted of 5 men and 3 women with incessant AVNRT. Patients with incessant AVNRT presented more frequently with the fast-slow form than those with paroxysmal AVNRT (63% vs. 14%, respectively, p < 0.001). The ejection fraction in patients with incessant AVNRT was significantly lower than that in patients with paroxysmal AVNRT (49 ± 12% vs. 60 ± 8%, p = 0.03). The H-V interval in patients with incessant AVNRT was significantly longer than that in patients with paroxysmal AVNRT. A large circuit path length is inferred by spontaneous tachycardia induction in response to slight changes in sinus rate or random premature beats, suggesting that slight changes in rate produce changes in atrial or nodal refractoriness and provoke SVT. Catheter ablation in the conventional slow pathway region was successful in eliminating SVT.
CONCLUSIONS
AVNRT can rarely present as incessant SVT, mimicking permanent junctional reciprocating tachycardia, and can be associated with tachycardia-associated cardiomyopathy. Catheter ablation in the slow pathway region leads to long-term success.
View on PubMed2016
BACKGROUND
Marijuana (hereafter "tetrahydrocannabinol [THC]") use has been associated with liver fibrosis progression in retrospective analyses of patients with chronic hepatitis C (HCV). We studied long-term effects of THC on fibrosis progression in women coinfected with human immunodeficiency virus (HIV)/HCV enrolled in the Women's Interagency HIV Study (WIHS).
METHODS
Liver fibrosis was categorized according to FIB-4 scores as none, moderate, or significant. THC and alcohol use were quantified as average exposure per week. Associations between THC use and progression to significant fibrosis were assessed using Cox proportional hazards regression.
RESULTS
Among 575 HIV/HCV-coinfected women followed for a median of 11 (interquartile range, 6-17) years, 324 (56%) reported no THC use, 141 (25%) less than weekly use, 70 (12%) weekly use, and 40 (7%) daily use at WIHS entry. In univariable analysis, entry FIB-4 score (hazard ratio [HR], 2.26 [95% confidence interval {CI}, 1.88-2.73], P < .001), log HCV RNA (HR, 1.19 [95% CI, 1.02-1.38], P = .02), tobacco use (HR, 1.37 [95% CI, 1.02-1.85], P = .04), CD4(+) count (risk per 100-cell increase: HR, 0.90 [95% CI, .86-.95], P < .001), and log HIV RNA (HR, 1.18 [95% CI, 1.05-1.32], P = .005) were associated with progression to significant fibrosis, as was cumulative alcohol use in follow-up (HR, 1.03 [95% CI, 1.02-1.04], P < .001). In multivariable analysis, entry FIB-4, entry CD4(+) count, and cumulative alcohol use remained significant. Cumulative THC use was not associated with fibrosis progression (HR, 1.01 [95% CI, .92-1.10], P = .83).
CONCLUSIONS
In this large cohort of HIV/HCV-coinfected women, THC was not associated with progression to significant liver fibrosis. Alcohol use was independently associated with liver fibrosis, and may better predict fibrosis progression in HIV/HCV-coinfected women.
View on PubMed2016
A novel blood-borne human pegivirus (HPgV), HPgV-2, was recently identified in hepatitis C virus (HCV)-infected individuals and individuals who had received multiple transfusions. Robust serological assays capable of detecting antibodies in HPgV-2-infected individuals are needed to establish global seroprevalence rates and potential disease associations. The two objectives of this study were to determine the utility of mammalian cell-expressed HPgV-2 E2 glycoprotein or bacterium-expressed nonstructural protein 4AB (NS4AB) in detecting past or present infections and to compare the total prevalence (antibody and RNA positive) of HPgV-2 with that of the other human pegivirus, HPgV-1 (GB virus C [GBV-C]). HPgV-2 E2 antibodies were detected in 13 (92.86%) of 14 HPgV-2-viremic cases, and NS4AB antibodies were detected in 8 (57.14%) of 14 cases. The HPgV-2 seroprevalence was significantly higher (P < 0.0001) among HCV-infected individuals (3.31% [24 of 726 samples]) than among non-HCV-infected individuals (0.30% [4 of 1,348 samples]). Of 31 anti-E2-positive samples, 22 had supplemental supporting data; 12 samples were HPgV-2 RNA positive and 10 nonviremic samples were antibody positive for peptides or NS4AB. The total prevalence of HPgV-1 (35.00%) was significantly higher than that of HPgV-2 (1.33%) in all populations tested (P < 0.0001). For HPgV-1, codetection of antibodies to E2 and RNA was infrequent (5.88%). In contrast, antibodies to E2 were detected in most HPgV-2-viremic individuals (92.86%), as is observed among individuals chronically infected with HCV, most of whom are antibody positive for HCV E2. Our studies indicate that HPgV-2 circulates with HCV and displays a profile similar to the serological profile of HCV-infected persons, although the pathogenicity of this virus has yet to be established.
View on PubMed2016
BACKGROUND
Young women undergoing percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) experience greater adverse events than men, potentially due to under-treatment. We sought to compare the 1-year outcomes by sex in patients ≤55 years of age from a contemporary PCI cohort.
METHODS
PROMETHEUS was a retrospective multicenter observational US study comparing outcomes in clopidogrel and prasugrel treated patients following ACS PCI. MACE was defined as a composite of death, myocardial infarction, stroke or unplanned revascularization. Clinically significant bleeding was defined as bleeding requiring transfusion or hospitalization. Hazard ratios were generated using multivariable Cox proportional hazards regression.
RESULTS
The study cohort included 4,851 patients of which 1,162 (24.0%) were women and 3,689 (76.0%) were men. In this cohort, the prevalence of diabetes (41.0 vs. 27.9%) and chronic kidney disease (12.7 vs. 7.2%) was higher among women compared with men. Irrespective of sex, prasugrel was used in less than one-third of patients (31.8% in men vs. 28.1% in women, P = 0.01). Unadjusted, 1-year MACE (21.1% vs. 16.2%, P < 0.001) and bleeding (3.6% vs. 2.2%, P = 0.01) was significantly higher in women compared with men, but these results were no longer significant after adjustment for risk (HR 1.13, 95% CI 0.94-1.36 for MACE and HR 1.31, 95% CI 0.85-2.04 for bleeding).
CONCLUSION
Women ≤ 55 years of age undergoing ACS PCI have significantly greater comorbidities than young men. Despite a higher risk clinical phenotype in women, prasugrel use was significantly lower in women than men. Female sex was associated with a significantly higher risk of 1-year MACE and bleeding than male sex, findings that are attributable to baseline differences. © 2016 Wiley Periodicals, Inc.
View on PubMed2016
Research has demonstrated the clinical effectiveness of pre-exposure prophylaxis (PrEP) for HIV prevention, but little is known about how factors at the individual-, interpersonal-, community-, and structural levels impact PrEP use for black men who have sex with men (BMSM). We advance existing work by examining how all levels of the ecological framework must be addressed for PrEP to be successfully implemented as an effective HIV prevention approach. We interviewed 31 BMSM three times each and 17 community stakeholders once each; interviews were taped, transcribed, and analyzed using the constant comparative method. Factors that influence how BMSM experienced PrEP emerged across all levels of the ecological framework: At the individual level, respondents were wary of giving medication to healthy people and of the potential side-effects. At the interpersonal level, BMSM believed that PrEP use would discourage condom use and that PrEP should only be one option for HIV prevention, not the main option. At the community level, men described not trusting the pharmaceutical industry and described PrEP as an option for others, not for themselves. At the structural level, BMSM talked about HIV and sexuality-related stigmas and how they must overcome those before PrEP engagement. BMSM are a key population in the US National HIV/AIDS Strategy, yet few individuals believe that PrEP would be personally helpful. Our research indicates the urgent need to raise awareness and address structural stigma and policies that could be substantial barriers to the scale-up and implementation of PrEP-related services.
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