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1.  Chronic Ingestion of H1-Antihistamines Increase Progression of Atherosclerosis in Apolipoprotein E-/- Mice 
PLoS ONE  2014;9(7):e102165.
Although increased serum histamine levels and H1R expression in the plaque are seen in atherosclerosis, it is not known whether H1R activation is a causative factor in the development of the disease, or is a host defense response to atherogenic signals. In order to elucidate how pharmacological inhibition of histamine receptor 1 (H1R) signaling affects atherogenesis, we administered either cetirizine (1 and 4 mg/kg. b.w) or fexofenadine (10 and 40 mg/kg. b.w) to ApoE−/− mice maintained on a high fat diet for three months. Mice ingesting a low dose of cetirizine or fexofenadine had significantly higher plaque coverage in the aorta and cross-sectional lesion area at the aortic root. Surprisingly, the higher doses of cetirizine or fexofenadine did not enhance atherosclerotic lesion coverage over the controls. The low dose of fexofenadine, but not cetirizine, increased serum LDL cholesterol. Interestingly, the expression of iNOS and eNOS mRNA was increased in aortas of mice on high doses of cetirizine or fexofenadine. This may be a compensatory nitric oxide (NO)-mediated vasodilatory mechanism that accounts for the lack of increase in the progression of atherosclerosis. Although the administration of cetirizine did not alter blood pressure between the groups, there was a positive correlation between blood pressure and lesion/media ratio at the aortic root in mice receiving the low dose of cetirizine. However, this association was not observed in mice treated with the high dose of cetirizine or either doses of fexofenadine. The macrophages or T lymphocytes densities were not altered by low doses of H1-antihistamines, whereas, high doses decreased the number of macrophages but not T lymphocytes. The number of mast cells was decreased only in mice treated with low dose of fexofenadine. These results demonstrate that chronic ingestion of low therapeutic doses of cetirizine or fexofenadine enhance progression of atherosclerosis.
doi:10.1371/journal.pone.0102165
PMCID: PMC4096593  PMID: 25020133
2.  Quantification of the transporter substrate fexofenadine in cell lysates by LC-MS/MS 
Drug-drug interactions at transporters present a significant and under-investigated clinical problem. Investigations of specific transporter functions and screening for potential drug-drug interactions, both in vitro and especially in vivo, will require validated experimental probes. Fexofenadine, an approved, well-tolerated drug, is a promising probe for studies of membrane transporter function. Although fexofenadine pharmacokinetics are known to be controlled by transporters, the contributions of individual transporters have not been defined. We have developed a rapid, specific, and sensitive analytical method for quantitation of fexofenadine to support this work. This LC-MS/MS method quantifies fexofenadine in cell lysates from in vitro studies using cetirizine as the internal standard. Cell lysates were prepared for analysis by acetonitrile precipitation. Analytes were then separated by gradient reverse-phase chromatography and analyzed by tandem mass spectrometry using the m/z 502.17/466.2 transition for fexofenadine and m/z 389.02/201.1 for cetirizine. The method exhibited a linear dynamic range of 1–500 ng/mL for fexofenadine in cell lysates. The lower limit of quantification was 1 ng/mL with a relative standard deviation of less than 5%. Intra- and inter-day precision and accuracy were within the limits presented in the FDA guidelines for bioanalysis. We also will validate this method to support not only the quantification of fexofenadine, but also other probe drugs for drug-drug interaction studies. This method for quantification will facilitate the use of fexofenadine as a probe drug for characterization of transporter activity.
doi:10.1002/rcm.5111
PMCID: PMC4076838  PMID: 21766379
Fexofenadine; cell lysate; probe drug; transporter
3.  Effects of Menthol on the Pharmacokinetics of Bupropion Among Black Smokers 
Nicotine & Tobacco Research  2012;14(6):688-693.
Introduction:
Despite the widespread use of mentholated cigarettes, lower cessation rates, and disproportionately high smoking–related morbidity among Blacks, the possible role of menthol in smokers’ response to pharmacotherapy has not been well-studied. This study examined the effects of menthol on the pharmacokinetic (PK) profiles of bupropion and its principal metabolites, hydroxybupropion, threohydrobupropion, and erythrohydrobupropion among Black smokers.
Methods:
After a 7-day placebo run-in period, participants received 150 mg bid sustained-release bupropion for 20–25 days. Blood samples were drawn for PK analysis on 2 occasions, 10–15 days after the commencement of bupropion while participants were still smoking (smoking phase) and at days 20–25 when they were asked not to smoke (nonsmoking phase).
Results:
18 smokers of nonmenthol cigarettes and 23 smokers of menthol cigarettes were enrolled in this study. No differences were found by menthol smoking status in the Cmax and area under the plasma concentration versus time curve (AUC) of bupropion and its metabolites in the smoking or nonsmoking phases. However, among menthol smokers, the AUC ratios of metabolite/bupropion were lower in the nonsmoking phase compared with the smoking phase (hydro/bup = 31.49 ± 18.84 vs. 22.95 ± 13.27, p = .04; erythro/bup = 1.99 ± 1.02 vs. 1.76 ± 0.75, p = .016; threo/bup = 11.77 ± 8.90 vs. 10.44 ± 5.63, p = .034). No significant differences were found in the metabolite/bup ratios between smoking and nonsmoking conditions among nonmenthol smokers.
Conclusions:
We did not find a significant effect of menthol compared with nonmenthol cigarette smoking on the PKs of bupropion and metabolites at steady state. More research is needed to advance the understanding of mechanisms underlying disparities in smoking cessation outcomes related to smoking of menthol cigarettes.
doi:10.1093/ntr/ntr268
PMCID: PMC3356293  PMID: 22318754
4.  Buspirone, fexofenadine, and omeprazole: Quantification of probe drugs and their metabolites in human plasma 
Probe drugs are critical tools for the measurement of drug metabolism and transport activities in human subjects. Often several probe drugs are administered simultaneously in a —cocktail . This cocktail approach requires efficient analytical methods for the simultaneous quantitation of multiple analytes. We have developed and validated a liquid chromatography-tandem mass spectrometry method for the simultaneous determination of three probe drugs and their metabolites in human plasma. The analytes include omeprazole and its metabolites omeprazole sulfone and 5-hydroxyomeprazole; buspirone and its metabolite 1-[2-pyrimidyl]-piperazine (1PP); and fexofenadine. These analytes and the internal standard lansoprazole were extracted from plasma using protein precipitation with acetonitrile. Gradient reverse-phase chromatography was performed with 7.5 mM ammonium bicarbonate and acetonitrile, and the analytes were quantified in positive ion electrospray mode with multiple reaction monitoring. The method was validated to quantify the concentration ranges of 1.0–1000 ng/ml for omeprazole, omeprazole sulfone, 5-hydroxyomeprazole, and fexofenadine; 0.1-100 ng/ml for buspirone, and 1.0-100 ng/ml for 1PP. These linear ranges span the plasma concentrations for all of the analytes from probe drug studies. The intra-day precision was between 2.1 –16.1%, and the accuracy ranged from 86 -115% for all analytes. Inter-day precision and accuracy ranged from 0.3 – 14% and from 90 – 110%, respectively. The lower limits of quantification were 0.1 ng/ml for buspirone and 1 ng/ml for all other analytes. This method provides a fast, sensitive, and selective analytical tool for quantification of the six analytes in plasma necessary to support the use of this probe drug cocktail in clinical studies.
doi:10.1016/j.jpba.2011.03.043
PMCID: PMC3100389  PMID: 21546194
Probe drug cocktail; Human plasma; Buspirone; Fexofenadine; Omeprazole
5.  FUNCTIONAL ANALYSIS AND TREATMENT OF MULTIPLY CONTROLLED INAPPROPRIATE MEALTIME BEHAVIOR 
Functional analyses identified children whose inappropriate mealtime behavior was maintained by escape and adult attention. Function-based extinction procedures were tested individually and in combination. Attention extinction alone did not result in decreases in inappropriate mealtime behavior or a significant increase in acceptance. By contrast, escape extinction alone resulted in a decrease in inappropriate mealtime behavior and an increase in acceptance. However, inappropriate mealtime behavior did not decrease to clinically acceptable levels. A combined extinction technique (i.e., escape and attention extinction) resulted in a decrease in inappropriate mealtime behavior to clinically acceptable levels and high and stable acceptance.
doi:10.1901/jaba.2009.42-641
PMCID: PMC2741064  PMID: 20190924
escape extinction; food refusal; food selectivity; negative reinforcement; pediatric feeding disorders
6.  Design, recruitment, and retention of African-American smokers in a pharmacokinetic study 
Background
African-Americans remain underrepresented in clinical research despite experiencing a higher burden of disease compared to all other ethnic groups in the United States. The purpose of this article is to describe the study design and discuss strategies used to recruit and retain African-American smokers in a pharmacokinetic study.
Methods
The parent study was designed to evaluate the differences in the steady-state concentrations of bupropion and its three principal metabolites between African-American menthol and non-menthol cigarette smokers. Study participation consisted of four visits at a General Clinical Research Center (GCRC) over six weeks. After meeting telephone eligibility requirements, phone-eligible participants underwent additional screening during the first two GCRC visits. The last two visits (pharmacokinetic study phase) required repeated blood draws using an intravenous catheter over the course of 12 hours.
Results
Five hundred and fifteen African-American smokers completed telephone screening; 187 were phone-eligible and 92 were scheduled for the first GCRC visit. Of the 81 who attended the first visit, 48 individuals were enrolled in the pharmacokinetic study, and a total of 40 individuals completed the study (83% retention rate).
Conclusions
Although recruitment of African-American smokers into a non-treatment, pharmacokinetic study poses challenges, retention is feasible. The results provide valuable information for investigators embarking on non-treatment laboratory-based studies among minority populations.
doi:10.1186/1471-2288-10-6
PMCID: PMC2850393  PMID: 20085641
7.  Single-Dose Pharmacokinetics and Tolerability of Absorption-Enhanced 3, 3′-Diindolylmethane in Healthy Subjects 
We have completed a single ascending dose clinical study of the proposed chemopreventive agent 3, 3′-dindolylmethane (DIM). The study agent was nutritional-grade, absorption-enhanced BioResponse® 3, 3′-diindolylmethane (BR-DIM). We determined the safety, tolerability, and pharmacokinetics of single doses of BR-DIM in drug-free, non-smoking, healthy men and women. Groups of four subjects were enrolled for each dose level. After randomization, one subject in each group received placebo while three received active BR-DIM. Doses administered were 50, 100, 150, 200, and 300 mg, with the 300 mg dose repeated in an additional group. No BR-DIM-related adverse effects were reported at doses up to 200 mg. At the 300 mg dose, one of six subjects reported mild nausea and headache and one also reported vomiting. Only the latter effect was judged as probably related to study agent. Analysis of serial plasma samples showed that only one subject at the 50 mg dose had detectable concentrations of DIM. The single 100 mg dose of BR-DIM resulted in a mean Cmax of 32 ng/ml, and a mean AUC of 128 hr*ng/ml, and a single 200 mg dose produced a mean Cmax of 104 ng/ml and a mean AUC of 553 hr*ng/ml. The single 300 mg dose of BR-DIM resulted in a mean Cmax of 108 ng/ml and a mean AUC of 532 hr*ng/ml. We conclude that BR-DIM is well tolerated at single doses of up to 200 mg, and that increasing the dose to 300 mg did not result in an increase in Cmax.
doi:10.1158/1055-9965.EPI-08-0520
PMCID: PMC2602858  PMID: 18843002
8.  DECREASED BRAIN DOCOSAHEXAENOIC ACID CONTENT PRODUCES NEUROBIOLOGICAL EFFECTS ASSOCIATED WITH DEPRESSION: INTERACTIONS WITH REPRODUCTIVE STATUS IN FEMALE RATS 
Psychoneuroendocrinology  2008;33(9):1279-1292.
Summary
Decreased tissue levels of docosahexaenoic acid (DHA; 22:6n-3) are implicated in the etiologies of non-puerperal and postpartum depression. With the aim of determining neurobiological sequelae of decreased brain DHA content, this study examined the effects of a loss of brain DHA content and concurrent reproductive status in adult female Long-Evans rats. An α-linolenic acid-deficient diet and breeding protocols were used to produce virgin and parous female rats with cortical phospholipid DHA levels 23–26% lower than virgin and parous rats fed a control diet containing adequate α-linolenic acid. Parous dams were tested/euthanized at weaning (postnatal day 20) of the second litter; virgin females, during diestrus. Decreased brain DHA was associated with decreased hippocampal BDNF gene expression and increased relative corticosterone response to an intense stressor, regardless of reproductive status. In virgin females with decreased brain DHA, serotonin content and turnover in frontal cortex were decreased compared to virgin females with normal brain DHA. In parous dams with decreased brain DHA, the density of 5-HT1A receptors in the hippocampus was increased, corticosterone response to an intense stressor was increased, and the latency to immobility in the forced swim test was decreased compared to parous dams with normal DHA. These findings demonstrate neurobiological alterations attributable to decreased brain DHA or an interaction of parous status and brain DHA level. Furthermore, the data are consistent with findings in depressed humans, and thus support a role for DHA as a factor in the etiologies of depressive illnesses, particularly postpartum depression.
doi:10.1016/j.psyneuen.2008.06.012
PMCID: PMC2582014  PMID: 18707812
omega-3 polyunsaturated fatty acid; brain-derived neurotrophic factor; serotonin 1A receptor; forced swim; postpartum; corticosterone
9.  Ozone and PM2.5 Exposure and Acute Pulmonary Health Effects: A Study of Hikers in the Great Smoky Mountains National Park 
Environmental Health Perspectives  2006;114(7):1044-1052.
To address the lack of research on the pulmonary health effects of ozone and fine particulate matter (≤ 2.5 μm in aerodynamic diameter; PM2.5) on individuals who recreate in the Great Smoky Mountains National Park (USA) and to replicate a study performed at Mt. Washington, New Hampshire (USA), we conducted an observational study of adult (18–82 years of age) day hikers of the Charlies Bunion trail during 71 days of fall 2002 and summer 2003. Volunteer hikers performed pre- and posthike pulmonary function tests (spirometry), and we continuously monitored ambient O3, PM2.5, temperature, and relative humidity at the trailhead. Of the 817 hikers who participated, 354 (43%) met inclusion criteria (nonsmokers and no use of bronchodilators within 48 hr) and gave acceptable and reproducible spirometry. For these 354 hikers, we calculated the posthike percentage change in forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), FVC/FEV1, peak expiratory flow, and mean flow rate between 25 and 75% of the FVC and regressed each separately against pollutant (O3 or PM2.5) concentration, adjusting for age, sex, hours hiked, smoking status (former vs. never), history of asthma or wheeze symptoms, hike load, reaching the summit, and mean daily temperature. O3 and PM2.5 concentrations measured during the study were below the current federal standards, and we found no significant associations of acute changes in pulmonary function with either pollutant. These findings are contrasted with those in the Mt. Washington study to examine the hypothesis that pulmonary health effects are associated with exposure to O3 and PM2.5 in healthy adults engaged in moderate exercise.
doi:10.1289/ehp.8637
PMCID: PMC1513325  PMID: 16835057
air pollution epidemiology; fine particulate matter exposure; Great Smoky Mountains National Park; ozone exposure; pulmonary function; spirometry
10.  The Effects Of Sleep Disruption On The Treatment Of A Feeding Disorder 
We evaluated the effects of sleep disruption on the mealtime behavior of a young boy with developmental disabilities. Results showed that bite acceptance was less likely to persist during meals following disrupted sleep, but only when escape extinction was not implemented. Findings are discussed in terms of establishing operations and the effects of sleep disruption on the assessment and treatment of feeding problems.
doi:10.1901/jaba.2005.42-04
PMCID: PMC1226160  PMID: 16033171
establishing operations; food refusal; pediatric feeding disorders; sleep disruption
11.  On the relative contributions of noncontingent reinforcement and escape extinction in the treatment of food refusal. 
In the current investigation, we evaluated the relative effects of noncontingent reinforcement (NCR), escape extinction, and a combination of NCR and escape extinction as treatment for the feeding problems exhibited by 4 children. For each participant, consumption increased only when escape extinction was implemented, independent of whether NCR was present or absent. These results were consistent with prior research suggesting that positive reinforcement alone is insufficient for increasing consumption, and that escape extinction often is necessary to increase and maintain food acceptance. However, NCR appeared to decrease inappropriate behavior for some participants.
doi:10.1901/jaba.2004.37-27
PMCID: PMC1284475  PMID: 15154213
12.  Differential reinforcement with and without instructional fading. 
We evaluated a differential-reinforcement-based treatment package for the reduction of problem behavior during instructional situations. Differential reinforcement of alternative behavior (DRA; compliance) was implemented across two conditions. During one condition, instructions were presented approximately once every other minute. This condition was considered the terminal goal for treatment. During the second condition, the rate of instructions was gradually increased (beginning at zero and ending when instruction rate was similar to the first condition). Results indicated that DRA with instructional fading resulted in less problem behavior than DRA without instructional fading. These results are similar to previous studies regarding the utility of instructional fading.
doi:10.1901/jaba.2002.35-291
PMCID: PMC1284388  PMID: 12365743
13.  Dopamine receptor alterations in female rats with diet-induced decreased brain docosahexaenoic acid (DHA): interactions with reproductive status 
Nutritional Neuroscience  2010;13(4):161-169.
Decreased tissue levels of n-3 (omega-3) fatty acids, particularly docosahexaenoic acid (DHA), are implicated in the etiologies of non-puerperal and postpartum depression. This study examined the effects of a diet-induced loss of brain DHA content and concurrent reproductive status on dopaminergic parameters in adult female Long–Evans rats. An α-linolenic acid-deficient diet and breeding protocols were used to produce virgin and parous female rats with cortical phospholipid DHA levels 20–22% lower than those fed a control diet containing adequate α-linolenic acid. Decreased brain DHA produced a significant main effect of decreased density of ventral striatal D2-like receptors. Virgin females with decreased DHA also exhibited higher density of D1-like receptors in the caudate nucleus than virgin females with normal DHA. These receptor alterations are similar to those found in several rodent models of depression, and are consistent with the proposed hypodopaminergic basis for anhedonia and motivational deficits in depression.
doi:10.1179/147683010X12611460764282
PMCID: PMC2955509  PMID: 20670471
omega-3; polyunsaturated fatty acid; dopamine receptor; postpartum; docosahexaenoic acid; rat

Results 1-13 (13)