Publications
Department of Medicine faculty members published more than 3,600 peer-reviewed articles in 2024.
2014
Exposure to levamisole-adulterated cocaine can induce a distinct clinical syndrome characterized by retiform purpura and/or agranulocytosis accompanied by an unusual constellation of serologic abnormalities including antiphospholipid antibodies, lupus anticoagulants, and very high titers of antineutrophil cytoplasmic antibodies. Two recent case reports suggest that levamisole-adulterated cocaine may also lead to renal disease in the form of pauci-immune glomerulonephritis. To explore this possibility, we reviewed cases of pauci-immune glomerulonephritis between 2010 and 2012 at an inner city safety net hospital where the prevalence of levamisole in the cocaine supply is known to be high. We identified 3 female patients and 1 male patient who had biopsy-proven pauci-immune glomerulonephritis, used cocaine, and had serologic abnormalities characteristic of levamisole-induced autoimmunity. Each also had some other form of clinical disease known to be associated with levamisole, either neutropenia or cutaneous manifestations. One patient had diffuse alveolar hemorrhage. Three of the 4 patients were treated with short courses of prednisone and cyclophosphamide, 2 of whom experienced stable long-term improvement in their renal function despite ongoing cocaine use. The remaining 2 patients developed end-stage renal disease and became dialysis-dependent. This report supports emerging concern of more wide spread organ toxicity associated with the use of levamisole-adulterated cocaine.
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BACKGROUND
Abnormal levels of CD8 T-cell activation persist in HIV-1-infected patients on suppressive antiretroviral therapy (ART) and may be deleterious.
METHODS
CD8 T-cell activation (% coexpressing CD38/HLA-DR) was analyzed on blood specimens from 833 HIV-1-infected patients on ART for ≥96 weeks with concurrent plasma HIV RNA (vRNA) ≤200 copies per milliliter. Factors associated with CD8 T-cell activation were assessed using generalized estimating equations to incorporate longitudinal measurements (median 4/participant).
RESULTS
Participants were 84% men, 47% white, 28% black, and 22% Hispanic, with median pre-ART age 38 years and median ART exposure 144 weeks. CD8 T-cell activation was higher at timepoints when vRNA was 51-200 versus ≤50 copies per milliliter [mean CD8 T-cell activation 23.4% vs. 19.7%; adjusted difference: 1.7% (95% confidence interval: 0.1 to 3.4), P = 0.042]. Restricting to vRNA ≤50 copies per milliliter, multivariable models showed the following factors associated with higher CD8 T-cell activation: older age [≥45 vs. ≤30 years: 3.6% (1.4 to 5.7), P = 0.004], hepatitis C virus antibody positivity [3.6% (0.9 to 6.2), P = 0.032], Hispanic vs. white [7.2% (5.3 to 9.0), P < 0.001], lower concurrent CD4 count [≤200 vs. >500 cells/mm: 2.2% (0.7 to 3.7), P < 0.001], lower concurrent CD4/CD8 ratio [-2.6% (-3.7 to -1.5) per 0.5 unit increase, P < 0.001], and higher pre-ART CD8 T-cell activation [2.0% (1.6 to 2.5) per 10% higher, P < 0.001].
CONCLUSIONS
In participants included in our analysis, residual low-level viremia between 51 and 200 copies per milliliter during ART was shown to be associated with greater CD8 T-cell activation than full suppression to <50 copies per milliliter. Older age, hepatitis C virus antibody positivity, race/ethnicity, higher pre-ART CD8 T-cell activation, and lower concurrent CD4/CD8 ratio and CD4 T-cell count also contribute to greater CD8 T-cell activation during suppressive ART.
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The limb is widely used as a model developmental system and changes to gene expression patterns in its signaling centers, notably the zone of polarizing activity (ZPA) and the apical ectodermal ridge (AER), are known to cause limb malformations and evolutionary differences in limb morphology. Although several genes that define these limb signaling centers have been described, the identification of regulatory elements that are active within these centers has been limited. By dissecting mouse E11.5 limbs that fluorescently mark the ZPA or AER, followed by fluorescence-activated cell sorting and low-cell H3K27ac ChIP-seq, we identified thousands of specific signaling-center enhancers. Our ChIP-seq datasets show strong correlation with ZPA- and AER-expressed genes, previously characterized functional ZPA and AER enhancers and enrichment for relevant biological terms related to limb development and malformation for the neighboring genes. Using transgenic assays, we show that several of these sequences function as ZPA and AER enhancers. Our results identify novel ZPA and AER enhancers that could be important regulators of genes involved in the establishment of these specialized regions and the patterning of tetrapod limbs.
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2014
OBJECTIVE
Systemic lupus erythematosus (SLE) has one of the highest hospital readmission rates among chronic conditions. This study was undertaken to identify patient-level, hospital-level, and geographic predictors of 30-day hospital readmissions associated with SLE.
METHODS
Using hospital discharge databases from 5 geographically dispersed states, we studied all-cause readmission of SLE patients between 2008 and 2009. We evaluated each hospitalization as a possible index event leading up to a readmission, our primary outcome. We accounted for clustering of hospitalizations within patients and within hospitals and adjusted for hospital case mix. Using multilevel mixed-effects logistic regression, we examined factors associated with 30-day readmission and calculated risk-standardized hospital-level and state-level readmission rates.
RESULTS
We examined 55,936 hospitalizations among 31,903 patients with SLE. Of these hospitalizations, 9,244 (16.5%) resulted in readmission within 30 days. In adjusted analyses, age was inversely related to risk of readmission. African American and Hispanic patients were more likely to be readmitted than white patients, as were those with Medicare or Medicaid insurance (versus private insurance). Several clinical characteristics of lupus, including nephritis, serositis, and thrombocytopenia, were associated with readmission. Readmission rates varied significantly between hospitals after accounting for patient-level clustering and hospital case mix. We also found geographic variation, with risk-adjusted readmission rates lower in New York and higher in Florida as compared to California.
CONCLUSION
We found that ~1 in 6 hospitalized patients with SLE were readmitted within 30 days of discharge, with higher rates among historically underserved populations. Significant geographic and hospital-level variation in risk-adjusted readmission rates suggests potential for quality improvement.
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2014