Publications
Department of Medicine faculty members published more than 3,000 peer-reviewed articles in 2022.
2017
INTRODUCTION
The apolipoprotein E () ε allele associates with memory impairment in neurodegenerative diseases. Its association with memory after mild traumatic brain injury (mTBI) is unclear.
METHODS
mTBI patients (Glasgow Coma Scale score 13-15, no neurosurgical intervention, extracranial Abbreviated Injury Scale score ≤1) aged ≥18 years with genotyping results were extracted from the Transforming Research and Clinical Knowledge in Traumatic Brain Injury Pilot (TRACK-TBI Pilot) study. Cohorts determined by ε were assessed for associations with 6-month verbal memory, measured by California Verbal Learning Test, Second Edition (CVLT-II) subscales: Immediate Recall Trials 1-5 (IRT), Short-Delay Free Recall (SDFR), Short-Delay Cued Recall (SDCR), Long-Delay Free Recall (LDFR), and Long-Delay Cued Recall (LDCR). Multivariable regression controlled for demographic factors, seizure history, loss of consciousness, posttraumatic amnesia, and acute intracranial pathology on computed tomography (CT).
RESULTS
In 114 mTBI patients (ε=79; ε=35), ε was associated with long-delay verbal memory deficits (LDFR: =-1.17 points, 95% CI [-2.33, -0.01], =.049; LDCR: =-1.58 [-2.63, -0.52], =.004), and a marginal decrease on SDCR (=-1.02 [-2.05, 0.00], =.050). CT pathology was the strongest predictor of decreased verbal memory (IRT: =-8.49, SDFR: =-2.50, SDCR: -1.85, LDFR: -2.61, LDCR: -2.60; <.001). Seizure history was associated with decreased short-term memory (SDFR: -1.32, =.037; SDCR: -1.44, =.038).
CONCLUSION
The ε allele may confer an increased risk of impairment of 6-month verbal memory for patients suffering mTBI, with implications for heightened surveillance and targeted therapies. Acute intracranial pathology remains the driver of decreased verbal memory performance at 6 months after mTBI.
View on PubMed2017
OBJECTIVE
For chronic heart failure (CHF), more emphasis has been placed on evaluation of systolic as opposed to diastolic function. Within the study of diastology, measurements of left ventricular (LV) longitudinal myocardial relaxation have the most validation. Anterior wall radial myocardial tissue relaxation velocities along with mitral valve inflow (MVI) patterns are applicable diastolic parameters in the differentiation between moderate and severe disease in the ischemic rat model of CHF. Myocardial tissue relaxation velocities correlate with traditional measurements of diastolic function (ie, hemodynamics, Tau, and diastolic pressure-volume relationships).
METHODS AND RESULTS
Male Sprague-Dawley rats underwent left coronary artery ligation or sham operation. Echocardiography was performed at 3 and 6 weeks after coronary ligation to evaluate LV ejection fraction (EF) and LV diastolic function through MVI patterns (E, A, and E/A) and Doppler imaging of the anterior wall (e' and a'). The rats were categorized into moderate or severe CHF according to their LV EF at 3 weeks postligation. Invasive hemodynamic measurements with solid-state pressure catheters were obtained at the 6-week endpoint. Moderate (N = 20) and severe CHF (N = 22) rats had significantly (P < .05) different EFs, hemodynamics, and diastolic pressure-volume relationships. Early diastolic anterior wall radial relaxation velocities as well as E/e' ratios separated moderate from severe CHF and both diastolic parameters had strong correlations with invasive hemodynamic measurements of diastolic function.
CONCLUSION
Radial anterior wall e' and E/e' can be used for serial assessment of diastolic function in rats with moderate and severe CHF.
View on PubMed2017
2017
2017
CONTEXT
Most of the reviews on the biological basis for symptom clusters suggest that inflammatory processes are involved in the development and maintenance of the symptom clusters. However, no studies have evaluated for associations between genetic polymorphisms and common symptom clusters (e.g., mood disturbance, sickness behavior).
OBJECTIVES
Examine the associations between cytokine gene polymorphisms and the severity of three distinct symptom clusters (i.e., mood-cognitive, sickness-behavior, treatment-related) in a sample of patients with breast and prostate cancer (n = 157) at the completion of radiation therapy.
METHODS
Symptom severity was assessed using the Memorial Symptom Assessment Scale. Symptom clusters were created using exploratory factor analysis. The associations between cytokine gene polymorphisms and the symptom cluster severity scores were evaluated using regression analyses.
RESULTS
Polymorphisms in C-X-C motif chemokine ligand 8 (CXCL8), interleukin (IL13), and nuclear factor kappa beta 2 (NFKB2) were associated with severity scores for the mood-cognitive symptom cluster. In addition to interferon gamma (IFNG1), the same polymorphism in NFKB2 (i.e., rs1056890) that was associated with the mood-cognitive symptom cluster score was associated with the sickness-behavior symptom cluster. Polymorphisms in interleukin 1 receptor 1 (IL1R1), IL6, and NFKB1 were associated with severity factor scores for the treatment-related symptom cluster.
CONCLUSION
Our findings support the hypotheses that symptoms that cluster together have a common underlying mechanism and the most common symptom clusters in oncology patients are associated polymorphisms in genes involved in a variety of inflammatory processes.
View on PubMed2017
BACKGROUND
Models that predict the risk of estrogen receptor (ER)-positive breast cancers may improve our ability to target chemoprevention. We investigated the contributions of sex hormones to the discrimination of the Breast Cancer Surveillance Consortium (BCSC) risk model and a polygenic risk score comprised of 83 single nucleotide polymorphisms.
METHODS
We conducted a nested case-control study of 110 women with ER-positive breast cancers and 214 matched controls within a mammography screening cohort. Participants were postmenopausal and not on hormonal therapy. The associations of estradiol, estrone, testosterone, and sex hormone binding globulin with ER-positive breast cancer were evaluated using conditional logistic regression. We assessed the individual and combined discrimination of estradiol, the BCSC risk score, and polygenic risk score using the area under the receiver operating characteristic curve (AUROC).
RESULTS
Of the sex hormones assessed, estradiol (OR 3.64, 95% CI 1.64-8.06 for top vs bottom quartile), and to a lesser degree estrone, was most strongly associated with ER-positive breast cancer in unadjusted analysis. The BCSC risk score (OR 1.32, 95% CI 1.00-1.75 per 1% increase) and polygenic risk score (OR 1.58, 95% CI 1.06-2.36 per standard deviation) were also associated with ER-positive cancers. A model containing the BCSC risk score, polygenic risk score, and estradiol levels showed good discrimination for ER-positive cancers (AUROC 0.72, 95% CI 0.65-0.79), representing a significant improvement over the BCSC risk score (AUROC 0.58, 95% CI 0.50-0.65).
CONCLUSION
Adding estradiol and a polygenic risk score to a clinical risk model improves discrimination for postmenopausal ER-positive breast cancers.
View on PubMed2017
Standard cell culture guidelines often use media supplemented with antibiotics to prevent cell contamination. However, relatively little is known about the effect of antibiotic use in cell culture on gene expression and the extent to which this treatment could confound results. To comprehensively characterize the effect of antibiotic treatment on gene expression, we performed RNA-seq and ChIP-seq for H3K27ac on HepG2 cells, a human liver cell line commonly used for pharmacokinetic, metabolism and genomic studies, cultured in media supplemented with penicillin-streptomycin (PenStrep) or vehicle control. We identified 209 PenStrep-responsive genes, including transcription factors such as ATF3 that are likely to alter the regulation of other genes. Pathway analyses found a significant enrichment for "xenobiotic metabolism signaling" and "PXR/RXR activation" pathways. Our H3K27ac ChIP-seq identified 9,514 peaks that are PenStrep responsive. These peaks were enriched near genes that function in cell differentiation, tRNA modification, nuclease activity and protein dephosphorylation. Our results suggest that PenStrep treatment can significantly alter gene expression and regulation in a common liver cell type such as HepG2, advocating that antibiotic treatment should be taken into account when carrying out genetic, genomic or other biological assays in cultured cells.
View on PubMed2017
The PARP inhibitor (PARPi) talazoparib may potentiate activity of chemotherapy and toxicity in cells vulnerable to DNA damage. This phase I study evaluated the safety, tolerability, pharmacokinetics, and efficacy of talazoparib and carboplatin. Pharmacokinetic modeling explored associations between DNA vulnerability and hematologic toxicity. Twenty-four patients (eight males; 16 females) with solid tumors were enrolled in four cohorts at 0.75 and 1 mg daily talazoparib and weekly carboplatin (AUC 1 and 1.5, every 2 weeks or every 3 weeks), including 14 patients (58%) with prior platinum treatment. Dose-limiting toxicities included grade 3 fatigue and grade 4 thrombocytopenia; the MTD was not reached. Grade 3/4 toxicities included fatigue (13%), neutropenia (63%), thrombocytopenia (29%), and anemia (38%). After cycle 2's dose, delays/reductions were required in all patients. One complete and two partial responses occurred in germline BRCA1/2 (gBRCA1/2) patients. Four patients showed stable disease beyond 4 months, three of which had known mutations in DNA repair pathways. Pharmacokinetic toxicity modeling suggests that after three cycles of carboplatin AUC 1.5 every 3 weeks and talazoparib 1 mg daily, neutrophil counts decreased 78% [confidence interval (CI), 87-68] from baseline in gBRCA carriers and 63% (CI, 72-55) in noncarriers ( < 0.001). Pharmacokinetic toxicity modeling suggests an intermittent, pulse dosing schedule of PARP inhibition, differentiated by gBRCA mutation status, may improve the benefit/risk ratio of combination therapy. Carboplatin and talazoparib showed efficacy in DNA damage mutation carriers, but hematologic toxicity was more pronounced in gBRCA carriers. Carboplatin is best combined with intermittent talazoparib dosing differentiated by germline and somatic DNA damage mutation carriers. .
View on PubMed2017