190 results on '"Stewart, Paul W."'
Search Results
152. Postmortem and ex vivo carbon monoxide ventilation reduces injury in rat lungs transplanted from non–heart-beating donors.
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Dong, Boming, Stewart, Paul W., and Egan, Thomas M.
- Abstract
Objective: We sought to determine whether ventilation of lungs after death in non–heart-beating donors with carbon monoxide during warm ischemia and ex vivo lung perfusion and after transplant would reduce ischemia-reperfusion injury and improve lung function. Methods: One hour after death, Sprague-Dawley rats were ventilated for another hour with 60% oxygen (control group) or 500 ppm carbon monoxide in 60% oxygen (CO-vent group; n=6/group). Then, lungs were flushed with 20 mL cold Perfadex, stored cold for 1 hour, then warmed to 37°C in an ex vivo lung perfusion circuit perfused with Steen solution. At 37°C, lungs were ventilated for 15 minutes with alveolar gas with or without 500 ppm carbon monoxide, then perfusion-cooled to 20°C, flushed with cold Perfadex and stored cold for 2 hours. The left lung was transplanted using a modified cuff technique. Recipients were ventilated with 60% oxygen with or without carbon monoxide. One hour after transplant, we measured blood gases from the left pulmonary vein and aorta, and wet-to-dry ratio of both lungs. The RNA and protein extracted from graft lungs underwent real-time polymerase chain reaction and Western blotting, and measurement of cyclic guanosine monophosphate by enzyme-linked immunosorbent assay. Results: Carbon monoxide ventilation begun 1 hour after death reduced wet/dry ratio after ex vivo lung perfusion. After transplantation, the carbon monoxide–ventilation group had better oxygenation; higher levels of tissue cyclic guanosine monophosphate, heme oxidase-1 expression, and p38 phosphorylation; reduced c-Jun N-terminal kinase phosphorylation; and reduced expression of interleukin-6 and interleukin-1β messenger RNA. Conclusions: Administration of carbon monoxide to the deceased donor and non–heart-beating donor lungs reduces ischemia-reperfusion injury in rat lungs transplanted from non–heart-beating donors. Therapy to the deceased donor via the airway may improve post-transplant lung function. [Copyright &y& Elsevier]
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- 2013
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153. Stress, social support, and substantiated maltreatment in the second and third years of life
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Kotch, Jonathan B., Browne, Dorothy C., Ringwalt, Christopher L., Dufort, Vincent, Ruina, Ellen, Stewart, Paul W., and Jung, Jin-Whan
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- 1997
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154. Subacute Pb Exposure During Development and Unbaited Tunnel Maze Performance in Mice
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Stewart, Paul W, Delbagno, Vincent, Ng, John, Burright, Richard, and Donovick, Peter
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- 1998
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155. Sustainable and equivalent improvements in symptoms and functional well‐being following viral cure from ledipasvir/sofosbuvir versus elbasvir/grazoprevir for chronic hepatitis C infection: Findings from the randomized PRIORITIZE trial.
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Evon, Donna M., Dong, Meichen, Reeve, Bryce B., Peter, Joy, Michael, Larry, Lok, Anna S., Nelson, David R., and Stewart, Paul W.
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CHRONIC hepatitis C , *VIRAL hepatitis , *HEPATITIS C virus , *ABDOMINAL pain , *SYMPTOMS , *WELL-being , *HEPATITIS C - Abstract
The PRIORITIZE trial (clinicaltrials.gov: NCT02786537) was the first comparative effectiveness study to directly compare ledipasvir/sofosbuvir (LDV/SOF) and elbasvir/grazoprevir (EBR/GZR) for the treatment of chronic hepatitis C virus (HCV). A secondary aim of this study was to compare LDV/SOF and EBR/GZR on sustainable changes in several HCV‐associated symptoms and functional well‐being in patients who achieved sustained virological response (SVR). PRIORITIZE, a randomized controlled trial conducted between 2016 and 2020, evaluated change in six PROMIS® symptom scores (fatigue, sleep disturbance, cognitive disturbance, nausea, diarrhoea, abdominal pain) and functional well‐being using the disease‐specific HCV‐PRO instrument. Survey assessments were administered at baseline, early post‐treatment (median = 6 months) and late post‐treatment (median = 21 months). Constrained longitudinal linear mixed‐effects models were used to evaluate within‐treatment change and between‐treatment differences. Data from 793 participants (average 55 years old, 57% male, 44% black, 17% with cirrhosis) were analysed. From baseline to early post‐treatment, 5 out of 6 symptoms and functional well‐being significantly improved (all p's <.05). In the LDV/SOF arm, mean changes ranged from −3.73 for nausea to −6.41 for fatigue and in the EBR/GZR, mean changes ranged from −2.19 for cognitive impairment to −4.67 for fatigue. Change of >3 points was consider clinically meaningful. Improvements in most symptoms slightly favoured LDV/SOF, although the magnitude of differences between the regimens were small. Both regimens demonstrated significant improvements in symptoms and functional well‐being that were sustained during the late post‐treatment phase. EBR/GZR and LDV/SOF regimens had clinically equivalent and durable improvements in HCV symptoms and functional well‐being up to two years after SVR. [ABSTRACT FROM AUTHOR]
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- 2022
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156. Human Immunodeficiency Virus Type 1 RNA in Breast-Milk Components.
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Hoffman, Irving F., Martinson, Francis E. A., Stewart, Paul W., Chilongozi, David A., Szu-Yun Leu, David A., Kazembe, Peter N., Banda, Topia, Dzinyemba, Willard, Joshi, Priya, Cohen, Myron S., and Fiscus, Susan A.
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RIBONUCLEASES , *BREAST milk , *HIV , *HIV infection genetics , *SERUM - Abstract
We conducted the present study to determine which of the 4 components of breast milk (whole milk, skim milk, lipid layer, and breast-milk cells) had the highest sensitivity and concentration of human immunodeficiency virus (HIV) type 1 RNA burden and to determine biological correlates to these factors. The probability of detection of HIV (sensitivity) and the concentration of HIV-1 RNA were both associated with the choice of milk component, CD4+ cell count, concentration of blood serum HIV-1 RNA, and the presence of breast inflammation. Whole milk demonstrated higher sensitivity and mean concentration than any other single component. Sensitivity was enhanced by analyzing all 4 components of breast milk. [ABSTRACT FROM AUTHOR]
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- 2003
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157. Elevated Virus Loads of Kaposi's Sarcoma-Associated Human Herpesvirus 8 Predict Kaposi's Sarcoma Disease Progression, but Elevated Levels of Human Immunodeficiency Virus Type 1 Do Not.
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Quinlivan, E. Byrd, Zhang, Chuan, Stewart, Paul W., Komoltri, Chulaluk, Davis, Michelle G., and Wehbie, Robert S.
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KAPOSI'S sarcoma , *HERPESVIRUSES - Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) is found in Kaposi's sarcoma (KS), multicentric Castleman's disease, and primary effusion lymphomas. To prospectively evaluate KSHV load as a biomarker for KS clinical status and prognosis in a cohort of men with AIDS-related KS, 2 quantitative polymerase chain reaction (PCR) assays were developed and tested to determine KSHV peripheral blood mononuclear cell (PBMC) virus loads. Most patients (13/15) with good-prognosis KS had ≤ 1.5 log KSHV copies/10[sup 5] PBMC by both quantitative competitive (QC) and real-time Applied Biosystems (ABI) PCR. Both assays provided 94% specificity for identifying the 16 patients without KS progression during 20 months of follow-up. QC-PCR and ABI-PCR exhibited 100% and 80% levels of diagnostic sensitivity, respectively, for identifying the 5 patients whose KS progressed. Neither dichotomized human immunodeficiency virus loads nor dichotomized CD4 counts predicted either KS progression or KS clinical stage (all positive predictive values <30%). These results are evidence that the quantity of circulating KSHV in KS patients is biologically meaningful and is measurable with sufficient accuracy to provide clinically useful information. [ABSTRACT FROM AUTHOR]
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- 2002
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158. Patient‐reported outcomes 12 months after hepatitis C treatment with direct‐acting antivirals: Results from the PROP UP study.
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Serper, Marina, Evon, Donna M., Amador, Jipcy, Stewart, Paul W., Sarkar, Souvik, Lok, Anna S., Sterling, Richard K., Reeve, Bryce B., Golin, Carol E., Rajender Reddy, K., Lim, Joseph K., Reau, Nancy, Nelson, David R., Di Bisceglie, Adrian M., and Fried, Michael W.
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ANTIVIRAL agents , *HEPATITIS C virus , *HEPATITIS C , *ABDOMINAL pain - Abstract
Background & Aims: The long‐term impact of hepatitis C virus (HCV) therapy with all‐oral direct‐acting antivirals (DAAs) on patient‐reported outcomes (PROs) has not been well‐described. We characterized changes in PROs from pre‐treatment to 12 months post‐treatment in a real‐world cohort. Methods: PROP UP was a multi‐centre observational cohort study of 1601 patients treated with DAAs at 11 US gastroenterology/hepatology practices from 2015 to 2017. PROs were evaluated pre‐treatment (T1) and 12 months post‐treatment (T5). A minimally important change (MIC) threshold was prespecified as >5% change in PRO scores from T1 to T5. Multivariable analyses identified predictors of change. Results: Three‐quarters of patients were 55 or older; 45% were female, 60% were white, 33% were black, nearly half had cirrhosis. The most commonly‐prescribed DAA regimens were sofosbuvir‐based (83%) and grazoprevir/elbasvir (11%). Study retention was >95%. On average, small improvements were observed at 3 months post‐treatment in all PROs and sustained at 12 months post‐treatment among patients with sustained virologic response (SVR). Clinically meaningful improvements were achieved in fatigue (mean change score: −3.7 [−4.2, −3.1]), sleep (mean change score: −3.1 [−3.7, −2.5]), abdominal pain (mean change score: −2.6 [−3.3, −1.9]) and functional well‐being (mean change score: −7.0 [−6.0, −8.0]). Symptom improvements were generally not sustained with no SVR (n = 52). Patients with cirrhosis and MELD ≥12 had the greatest improvements in functional well‐being (−12.9 [−17.6, −8.1]). Conclusions: The improvements in patient‐reported outcomes reported by patients who achieved SVR following HCV DAA therapy were durable at 12 months post‐treatment. [ABSTRACT FROM AUTHOR]
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- 2021
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159. Patient-reported symptoms during and after direct-acting antiviral therapies for chronic hepatitis C: The PROP UP study.
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Evon, Donna M., Sarkar, Souvik, Amador, Jipcy, Lok, Anna S., Sterling, Richard K., Stewart, Paul W., Reeve, Bryce B., Serper, Marina, Reau, Nancy, Rajender Reddy, K., Di Bisceglie, Adrian M., Nelson, David R., Golin, Carol E., Lim, Joseph K., and Fried, Michael W.
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CHRONIC hepatitis C , *HEPATITIS C , *HEPATITIS C virus - Abstract
• Overall change in symptoms and functioning on DAAs was not clinically meaningful. • Patient experiences are very heterogeneous. • Patients prescribed one DAA regimen experienced the worst symptoms. • Patients that were cured had clinical improvements in fatigue, sleep, and functioning. • Patients who were not cured had minimal improvements. A comprehensive analysis of changes in symptoms and functioning during and after direct-acting antiviral (DAA) therapy for chronic hepatitis C virus (HCV) infection has not been conducted for patients treated in real-world clinical settings. Therefore, we evaluated patient-reported outcomes (PROs) in a diverse cohort of patients with HCV treated with commonly prescribed DAAs. PROP UP is a US multicenter observational study of 1,601 patients with HCV treated with DAAs in 2016-2017. PRO data were collected at baseline (T1), early on-treatment (T2), late on-treatment (T3) and 3-months post-treatment (T4). PRO mean change scores were calculated from baseline and a minimally important change (MIC) threshold was set at 5%. Regression analyses investigated patient and treatment characteristics independently associated with PRO changes on-treatment and post-treatment. Of 1,564 patients, 55% were male, 39% non-white, 47% had cirrhosis. Sofosbuvir/ledipasvir was prescribed to 63%, sofosbuvir/velpatasvir to 21%, grazoprevir/elbasvir to 11%, and paritaprevir/ombitasvir/ritonavir + dasabuvir to 5%. During DAA therapy, mean PRO scores improved slightly in the overall cohort, but did not reach the 5% MIC threshold. Between 21–53% of patients experienced >5% improved PROs while 23–36% experienced >5% worse symptoms. Of 1,410 patients with evaluable sustained virologic response (SVR) data, 95% achieved SVR. Among those with SVR, all mean PRO scores improved, with the 5% MIC threshold met for fatigue, sleep disturbance, and functioning well-being. Regression analyses identified subgroups, defined by age 35–55, baseline mental health issues and a higher number of health comorbidities as predictors of PRO improvements. In real-world clinical practices, we observed heterogeneous patient experiences during and after DAA treatment. Symptom improvements were more pronounced in younger patients, those with baseline mental health issues and multiple comorbidities. Patients who received direct-acting antiviral medications for hepatitis C at several liver centers in the US did not generally experience significant changes in baseline symptoms during treatment. We observed a full range of patient experiences with some patients experiencing substantial symptom improvements, yet others experiencing less improvements and some even experiencing a worsening of symptoms. The 1,346 patients who were cured of hepatitis C experienced improvements in fatigue, sleep disturbance, and functional well-being, and trends for improved pain and depression; whereas the 64 who were not cured experienced minimal improvements. Clinicaltrial.gov: NCT02601820. [ABSTRACT FROM AUTHOR]
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- 2019
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160. Medically tailored meals for food insecurity and type 2 diabetes: Protocol for the Food as Medicine for Diabetes (FAME-D) trial.
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Berkowitz, Seth A., Kruse, Gina R., Ball Ricks, Katharine A., Burch, Jessica, Ouimet, Ethan, Kitzis, Beth, Forrest, Colleen, Terranova, Jean, Stewart, Paul W., Buse, John B., Keyserling, Thomas C., Wexler, Deborah J., and Delahanty, Linda M.
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TYPE 2 diabetes , *FOOD security , *MEDICAL protocols , *QUALITY of life , *DIABETES - Abstract
Food insecurity is associated with worse glycemic management for individuals with type 2 diabetes mellitus (T2DM), but whether medically tailored meals (MTM), a food insecurity intervention, can improve glycemic management is unclear. To describe the protocol for a trial assessing whether an MTM plus lifestyle intervention improves hemoglobin A1c (HbA1c) and participant-reported outcomes, relative to a food subsidy (money that can be spent on foods participants choose), for adults with both T2DM and food insecurity. The Food as Medicine for Diabetes (FAME-D) randomized clinical trial (goal n = 200) is a pragmatic trial with an active comparator. Participants, who will have T2DM and report food insecurity, will be randomly assigned to a 6-month MTM plus telephone-delivered lifestyle change intervention, or a 6-month food subsidy ($40/month). The primary outcome is HbA1c at 6 months. Secondary outcomes include HbA1c at 12 months to assess whether the intervention effect (if any) is sustained, along with weight, food insecurity, diabetes distress, and health-related quality of life. Qualitative analyses of semi-structured interviews will help understand why, how, and under what circumstances the intervention achieved its observed results. Results from FAME-D will help inform clinical management of food insecurity when it co-occurs with T2DM. Further, results may be useful as healthcare payors are considering coverage for MTM interventions. ClinicalTrials.gov : NCT04828785 [ABSTRACT FROM AUTHOR]
- Published
- 2023
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161. Altered Bile Acid Metabolome in Patients with Nonalcoholic Steatohepatitis.
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Ferslew, Brian, Xie, Guoxiang, Johnston, Curtis, Su, Mingming, Stewart, Paul, Jia, Wei, Brouwer, Kim, Sidney Barritt, A., Ferslew, Brian C, Johnston, Curtis K, Stewart, Paul W, Brouwer, Kim L R, Sidney Barritt, A 4th, and Barritt, A Sidney 4th
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BIOCHEMISTRY , *COMPARATIVE studies , *DISCRIMINANT analysis , *FASTING , *FATTY liver , *INGESTION , *LIQUID chromatography , *MASS spectrometry , *RESEARCH methodology , *MEDICAL cooperation , *REGRESSION analysis , *RESEARCH , *TIME , *EVALUATION research , *CASE-control method , *DIAGNOSIS - Abstract
Background and Aims: The prevalence of nonalcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) is increasing at an alarming rate. The role of bile acids in the development and progression of NAFLD to NASH and cirrhosis is poorly understood. This study aimed to quantify the bile acid metabolome in healthy subjects and patients with non-cirrhotic NASH under fasting conditions and after a standardized meal.Methods: Liquid chromatography tandem mass spectroscopy was used to quantify 30 serum and 16 urinary bile acids from 15 healthy volunteers and 7 patients with biopsy-confirmed NASH. Bile acid concentrations were measured at two fasting and four post-prandial time points following a high-fat meal to induce gallbladder contraction and bile acid reabsorption from the intestine.Results: Patients with NASH had significantly higher total serum bile acid concentrations than healthy subjects under fasting conditions (2.2- to 2.4-fold increase in NASH; NASH 2595-3549 µM and healthy 1171-1458 µM) and at all post-prandial time points (1.7- to 2.2-fold increase in NASH; NASH 4444-5898 µM and healthy 2634-2829 µM). These changes were driven by increased taurine- and glycine-conjugated primary and secondary bile acids. Patients with NASH exhibited greater variability in their fasting and post-prandial bile acid profile.Conclusions: Results indicate that patients with NASH have higher fasting and post-prandial exposure to bile acids, including the more hydrophobic and cytotoxic secondary species. Increased bile acid exposure may be involved in liver injury and the pathogenesis of NAFLD and NASH. [ABSTRACT FROM AUTHOR]- Published
- 2015
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162. An Evaluation of HIV Testing Among Inmates in the North Carolina Prison System.
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Rosen, David L., Schoenbach, Victor J., Wohl, David A., White, Becky L., Stewart, Paul W., and Golin, Carol E.
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PRISONERS , *DIAGNOSIS of HIV infections , *HIV infection risk factors , *RISK-taking behavior , *PUBLIC health research , *DISEASES - Abstract
Objectives. We examined the use of voluntary HIV testing among state prisoners in the North Carolina prison system. Methods. We calculated system-wide and facility-specific proportions and rates of adult inmates tested for HIV and estimated associations between testing status and inmate characteristics for prisoners in North Carolina. Results. Of the 54016 inmates who entered prison between January 2004 and May 2006,20820 (38%) were tested for HIV; of those tested,18574 (89%) were tested at admission. Across the 8 intake prisons, more than 80% of inmates in both female facilities but less than 15% of inmates in 4 of 6 male facilities were tested. Prisoners with a documented history of heroin use, crack or cocaine use, conventional HIV risk behavior, or tuberculosis were at least 10% more likely to be tested than were inmates without these characteristics. However, more than 60% of men reporting conventional risk behaviors were not tested. Before covariate adjustment, Black men were 30% less likely than White men to be tested; in the multivariable regression model, this difference was attenuated to 13%. Conclusions. Rates of HIV testing varied widely across intake prisons, and many male inmates with documented risk of infection were never tested. (Am J Public Health. 2009;99:S452-S459. doi:10.2105/AJPH.2007.133124) [ABSTRACT FROM AUTHOR]
- Published
- 2009
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163. Characteristics and Behaviors Associated With HIV Infection Among Inmates in the North Carolina Prison System.
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Rosen, David L., Schoenbach, Victor J., Wohl, David A., White, Becky L., Stewart, Paul W., and Golin, Carol E.
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HIV infections , *IMPRISONMENT , *PRISONERS' sexual behavior , *AIDS risk factors , *PREVENTION of sexually transmitted diseases , *PREVENTION ,NORTH Carolina. Dept. of Corrections - Abstract
Objectives. We identified factors associated with testing HIV positive in a prison system performing voluntary HIV testing on inmates and estimated the number of undetected HIV cases to evaluate the efficacy of risk-factor-based HIV testing. Methods. We used logistic regression to estimate associations between HIV serostatus and HIV risk behaviors, mental health, coinfection status, and sociodemographic characteristics for prisoners entering the North Carolina Department of Correction from January 2004 through May 2006. We estimated the number of undetected HIV cases on the basis of age-, gender-, and race-specific HIV prevalences among prisoners and in the state. Results. Nearly 3.4% (718/21419) of tested prisoners were HIV positive. The strongest risk factors for infection among men were having sex with men (odds ratio [OR] = 8.0), Black race (OR = 6.2), other non-White race (OR = 7.4), and being aged 35 to 44 years (OR=4.1). The strongest risk factor among women was Black race (OR=3.8). Among HIV-positive prisoners, 65% were coinfected with HCV. We estimated that between 24% (223) and 61% (1101) of HIV cases remained undetected. Conclusions. The associations between HIV serostatus and a variety of factors highlight the potential limitations of risk-factor-based HIV testing in prisons, as do the high number of potential undetected HIV cases. [ABSTRACT FROM AUTHOR]
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- 2009
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164. Reply to: "Patient-reported symptoms during direct-acting antiviral treatment: A real-life study in HIV-HCV coinfected patients (ANRS CO13 HEPAVIH)".
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Evon, Donna M., Sarkar, Souvik, Amador, Jipcy, Lok, Anna S., Sterling, Richard K., Stewart, Paul W., Reeve, Bryce B., Serper, Marina, Reau, Nancy, Reddy, K. Rajender, Di Bisceglie, Adrian M., Nelson, David R., Golin, Carol E., Lim, Joseph K., and Fried, Michael W.
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CHRONIC hepatitis C - Abstract
Reply to: "Patient-reported symptoms during direct-acting antiviral treatment: A real-life study in HIV-HCV coinfected patients (ANRS CO13 HEPAVIH)" However, these discrepancies highlight the need for additional subgroup analyses because patient experiences appear to be quite heterogeneous during and after DAA therapy. Table 1 PROP UP HIV/HCV-coinfected patients' mean scores and change scores during DAA therapy. [Extracted from the article]
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- 2020
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165. Aminotransferase elevations in healthy adults receiving 4 grams of acetaminophen daily: a randomized controlled trial.
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Watkins PB, Kaplowitz N, Slattery JT, Colonese CR, Colucci SV, Stewart PW, Harris SC, Watkins, Paul B, Kaplowitz, Neil, Slattery, John T, Colonese, Connie R, Colucci, Salvatore V, Stewart, Paul W, and Harris, Stephen C
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Context: During a clinical trial of a novel hydrocodone/acetaminophen combination, a high incidence of serum alanine aminotransferase (ALT) elevations was observed.Objective: To characterize the incidence and magnitude of ALT elevations in healthy participants receiving 4 g of acetaminophen daily, either alone or in combination with selected opioids, as compared with participants treated with placebo.Design, Setting, and Participants: A randomized, single-blind, placebo-controlled, 5-treatment, parallel-group, inpatient, diet-controlled (meals provided), longitudinal study of 145 healthy adults in 2 US inpatient clinical pharmacology units.Intervention: Each participant received either placebo (n = 39), 1 of 3 acetaminophen/opioid combinations (n = 80), or acetaminophen alone (n = 26). Each active treatment included 4 g of acetaminophen daily, the maximum recommended daily dosage. The intended treatment duration was 14 days. Main Outcomes Serum liver chemistries and trough acetaminophen concentrations measured daily through 8 days, and at 1- or 2-day intervals thereafter.Results: None of the 39 participants assigned to placebo had a maximum ALT of more than 3 times the upper limit of normal. In contrast, the incidence of maximum ALT of more than 3 times the upper limits of normal was 31% to 44% in the 4 treatment groups receiving acetaminophen, including those participants treated with acetaminophen alone. Compared with placebo, treatment with acetaminophen was associated with a markedly higher median maximum ALT (ratio of medians, 2.78; 95% confidence interval, 1.47-4.09; P<.001). Trough acetaminophen concentrations did not exceed therapeutic limits in any participant and, after active treatment was discontinued, often decreased to undetectable levels before ALT elevations resolved.Conclusions: Initiation of recurrent daily intake of 4 g of acetaminophen in healthy adults is associated with ALT elevations and concomitant treatment with opioids does not seem to increase this effect. History of acetaminophen ingestion should be considered in the differential diagnosis of serum aminotransferase elevations, even in the absence of measurable serum acetaminophen concentrations. [ABSTRACT FROM AUTHOR]- Published
- 2006
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166. Cigarette smoking, stress-induced analgesia and pain perception in men and women
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Girdler, Susan S., Maixner, William, Naftel, Herman A., Stewart, Paul W., Moretz, Rebecca L., and Light, Kathleen C.
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SMOKING , *CIGARETTES , *ANALGESIA , *PAIN - Abstract
Abstract: This study examined gender differences in smoking-related analgesia and stress-induced analgesia (SIA), as a function of pain modality. Forty men (20 smokers, 20 nonsmokers) and 37 women (17 smokers) were tested twice for pain sensitivity to tourniquet ischemia, thermal heat, and cold pressor tests; once following mental stress and once following rest control, counterbalancing order. Cardiovascular and neuroendocrine responses to mental stress were also examined. While expected gender differences in pain sensitivity were observed, women smokers had greater threshold and tolerance times to ischemic pain than women nonsmokers (P<0.05) when pain testing followed rest. Male smokers had greater threshold and tolerance to cold pressor pain than male nonsmokers (P<0.05) after both rest and stress. Only women showed evidence for SIA, since women nonsmokers demonstrated greater ischemic pain threshold and tolerance following mental stress versus rest (P<0.05), and all women reported lower thermal heat pain unpleasantness after stress versus rest (P=0.05). Only nonsmokers showed expected inverse relationships between sympathetic and hypothalamic–pituitary–adrenal (HPA) axis reactivity measures and sensitivity to pain. Smokers showed evidence for blunted HPA-axis function at rest and stress. These results indicate that analgesia related to both being a smoker and stress is influenced by gender and pain modality. The reduced pain perception in smokers and absence of relationships between endogenous pain regulatory mechanisms and pain sensitivity may reflect a maladaptive response to chronic smoking. [Copyright &y& Elsevier]
- Published
- 2005
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167. A New Method for Choosing Sample Size for Confidence Interval--Based Inferences.
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Jiroutek, Michael R., Muller, Keith E., Kupper, Lawrence L., and Stewart, Paul W.
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SAMPLE size (Statistics) , *INFERENCE (Logic) , *CONFIDENCE intervals , *MATHEMATICAL models , *LINEAR programming , *GAUSSIAN processes - Abstract
Scientists often need to test hypotheses and construct corresponding confidence intervals. In designing a study to test a particular null hypothesis,traditional methods lead to a sample size large enough to provide sufficient statistical power. In contrast, traditional methods based on constructing a confidence interval lead to a sample size likely to control the width of the interval. With either approach, a sample size so large as to waste resources or introduce ethical concerns is undesirable. This work was motivated by the concern that existing sample size methods often make it difficult for scientists to achieve their actual goals. We focus on situations which involve a fixed, unknown scalar parameter representing the true state of nature. The width of the confidence interval is defined as the difference between the (random) upper and lower bounds. An event width is said to occur if the observed confidence interval width is less than a fixed constant chosen a priori. An event validity is said to occur if the parameter of interest is contained between the observed upper and lower confidence interval bounds. An event rejection is said to occur if the confidence interval excludes the null value of the parameter. In our opinion,scientists often implicitly seek to have all three occur: width, validity, and rejection. New results illustrate that neglecting rejection or width (and less so validity) often provides a sample size with a low probability of the simultaneous occurrence of all three events. We recommend considering all three events simultaneously when choosing a criterion for determining a sample size. We provide new theoretical results for any scalar (mean) parameter in a general linear model with Gaussian errors and fixed predictors. Convenient computational forms are included, as well as numerical... [ABSTRACT FROM AUTHOR]
- Published
- 2003
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168. Chilbearing patterns in a cohort of women sexually abused as children.
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Herman-Giddens, Marcia E., Kotch, Jonathan B., Browne, Dorothy C., Ruina, Ellen, Winsor, Jane R., Jung, Jin-Whan, and Stewart, Paul W.
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CHILDBIRTH , *MOTHERS , *CHILD sexual abuse - Abstract
Examines childbearing patterns among women victims of child sexual abuse in North Carolina. Age at birth of first child; Parity; Comparison with nonabused mothers; Number of children.
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- 1998
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169. Monthly haemostatic factor variability in women and men
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Stephen Holleran, Russell P. Tracy, Michael Lefevre, Abby G. Ershow, Paul W. Stewart, Roberta G. Reed, Alison M. Hill, Penny M. Kris-Etherton, Thomas A. Pearson, Mark K. Fung, Henry N. Ginsberg, Patricia J. Elmer, Hill, Alison M, Stewart, Paul W, Fung, Mark K, Kris-Etherton, Penny M, Ginsberg, Henry N, Tracy, Russell P, Pearson, Thomas A, Lefevre, Michael, Reed, Roberta G, Elmer, Patricia J, Holleran, Stephen, and Ershow, Abby G
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Adult ,Male ,Periodicity ,medicine.medical_specialty ,media_common.quotation_subject ,Clinical Biochemistry ,controlled dietary intervention ,Fibrinogen ,Biochemistry ,menstrual cycle ,Article ,plasminogen activator inhibitor ,Young Adult ,chemistry.chemical_compound ,Sex Factors ,Internal medicine ,Plasminogen Activator Inhibitor 1 ,Humans ,Medicine ,Young adult ,Menstrual Cycle ,Progesterone ,Menstrual cycle ,Aged ,media_common ,Estradiol ,Factor VII ,business.industry ,General Medicine ,Luteinizing Hormone ,Middle Aged ,Postmenopause ,Endocrinology ,Premenopause ,chemistry ,Plasminogen activator inhibitor-1 ,Components of variance ,Linear Models ,Female ,fibrinogen ,Luteinizing hormone ,business ,Hormone ,medicine.drug - Abstract
Background Hormonal status influences haemostatic factors including fibrinogen, factor VII and plasminogen activator inhibitor (PAI-1), and concentrations differ among men, premenopausal and postmenopausal women. This study examines how phases of the menstrual cycle influence variability of fibrinogen, factor VII and PAI-1. Design We studied 103 subjects (39 premenopausal women, 18 postmenopausal women and 46 men) during three, randomized, 8-week energy- and nutrient-controlled experimental diets in the Dietary Effects on Lipids and Thrombogenic Activity (DELTA) Study. Fasting blood samples were collected weekly during the last 4 weeks of each diet period, and haemostatic factors were quantified. Two linear mixed-effects models were used for fibrinogen, factor VII and PAI-1: one to estimate and compare group-specific components of variance, and the other to estimate additional fixed effects representing cyclical functions of day of menstrual cycle in premenopausal women. Results Systematic cyclical variation with day of menstrual cycle was observed for fibrinogen (P
- Published
- 2014
170. Child Adult Relationship Enhancement in Primary Care (PriCARE): study design/protocol for a randomized trial of a primary care-based group parenting intervention to prevent child maltreatment.
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Schilling S, Powell BJ, Stewart PW, and Wood JN
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- Child, Humans, Adult, Child, Preschool, Parenting, Parents education, Primary Health Care, Parent-Child Relations, Randomized Controlled Trials as Topic, Multicenter Studies as Topic, Problem Behavior, Child Abuse prevention & control
- Abstract
Background: Child maltreatment (CM) is a pervasive public health problem and there is a critical need for brief, effective, scalable prevention programs. Problematic parent-child relationships lie at the heart of CM. Parents who maltreat their children are more likely to have punitive parenting styles characterized by high rates of negative interaction and ineffective discipline strategies with over-reliance on punishment. Thus, parenting interventions that strengthen parent-child relationships, teach positive discipline techniques, decrease harsh parenting, and decrease child behavioral problems hold promise as CM prevention strategies. Challenges in engaging parents, particularly low-income and minority parents, and a lack of knowledge regarding effective implementation strategies, however, have greatly limited the reach and impact of parenting interventions. Child Adult Relationship Enhancement in Primary Care (PriCARE)/Criando Niños con CARIÑO is a 6-session group parenting intervention that holds promise in addressing these challenges because PriCARE/CARIÑO was (1) developed and iteratively adapted with input from racially and ethnically diverse families, including low-income families and (2) designed specifically for implementation in primary care with inclusion of strategies to align with usual care workflow to increase uptake and retention., Methods: This study is a multicenter randomized controlled trial with two parallel arms. Children, 2-6 years old with Medicaid/CHIP/no insurance, and their English- and Spanish-speaking caregivers recruited from pediatric primary care clinics in Philadelphia and North Carolina will be enrolled. Caregivers assigned to the intervention regimen will attend PriCARE/CARIÑO and receive usual care. Caregivers assigned to the control regimen will receive usual care only. The primary outcome is occurrence of an investigation for CM by child protective services during the 48 months following completion of the intervention. In addition, scores for CM risk, child behavior problems, harsh and neglectful parenting behaviors, caregiver stress, and caregiver-child interactions will be assessed as secondary outcome measures and for investigation of possible mechanisms of intervention-induced change. We will also identify PriCARE/CARIÑO implementation factors that may be barriers and facilitators to intervention referrals, enrollment, and attendance., Discussion: By evaluating proximal outcomes in addition to the distal outcome of CM, this study, the largest CM prevention trial with individual randomization, will help elucidate mechanisms of change and advance the science of CM prevention. This study will also gather critical information on factors influencing successful implementation and how to optimize intervention referrals, enrollment, and attendance to inform future dissemination and practical applications., Trial Registration: This trial was registered on ClinicalTrials.gov (NCT05233150) on February 1, 2022, prior to enrolling subjects., (© 2023. The Author(s).)
- Published
- 2023
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171. Biodistribution of Biomimetic Drug Carriers, Mononuclear Cells, and Extracellular Vesicles, in Nonhuman Primates.
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Haney MJ, Yuan H, Shipley ST, Wu Z, Zhao Y, Pate K, Frank JE, Massoud N, Stewart PW, Perlmutter JS, and Batrakova EV
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- Animals, Biomimetics, Leukocytes, Mononuclear, Macaca mulatta, Positron Emission Tomography Computed Tomography, Tissue Distribution, Drug Carriers metabolism, Extracellular Vesicles metabolism
- Abstract
Discovery of novel drug delivery systems to the brain remains a key task for successful treatment of neurodegenerative disorders. Herein, the biodistribution of immunocyte-based carriers, peripheral blood mononuclear cells (PBMCs), and monocyte-derived EVs are investigated in adult rhesus macaques using longitudinal PET/MRI imaging.
64 Cu-labeled drug carriers are introduced via different routes of administration: intraperitoneal (IP), intravenous (IV), or intrathecal (IT) injection. Whole body PET/MRI (or PET/CT) images are acquired at 1, 24, and 48 h post injection of64 Cu-labeled drug carriers, and standardized uptake values (SUVmean and SUVmax ) in the main organs are estimated. The brain retention for both types of carriers increases based on route of administration: IP < IV < IT. Importantly, a single IT injection of PBMCs produces higher brain retention compared to IT injection of EVs. In contrast, EVs show superior brain accumulation compared to the cells when administered via IP and IV routes, respectively. Finally, a comprehensive chemistry panel of blood samples demonstrates no cytotoxic effects of either carrier. Overall, living cells and EVs have a great potential to be used for drug delivery to the brain. When identifying the ideal drug carrier, the route of administration could make big differences in CNS drug delivery., (© 2021 The Authors. Advanced Biology published by Wiley-VCH GmbH.)- Published
- 2022
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172. A Pragmatic, Randomized Controlled Trial of Oral Antivirals for the Treatment of Chronic Hepatitis C: The PRIORITIZE Study.
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Sulkowski MS, Moon JS, Sherman KE, Morelli G, Darling JM, Muir AJ, Khalili M, Fishbein DA, Hinestrosa F, Shiffman ML, Di Bisceglie A, Rajender Reddy K, Pearlman B, Lok AS, Fried MW, Stewart PW, Peter J, Wadsworth S, Kixmiller S, Sloan A, Vainorius M, Horne PM, Michael L, Dong M, Evon DM, Segal JB, and Nelson DR
- Subjects
- 2-Naphthylamine administration & dosage, Administration, Oral, Adolescent, Adult, Aged, Aged, 80 and over, Anilides administration & dosage, Benzimidazoles administration & dosage, Benzofurans administration & dosage, Cyclopropanes administration & dosage, Drug Combinations, Drug Therapy, Combination methods, Female, Fluorenes administration & dosage, Follow-Up Studies, Genotyping Techniques, Hepacivirus genetics, Hepatitis C, Chronic blood, Hepatitis C, Chronic diagnosis, Hepatitis C, Chronic virology, Humans, Imidazoles administration & dosage, Lactams, Macrocyclic administration & dosage, Male, Middle Aged, Proline administration & dosage, Proline analogs & derivatives, Quinoxalines administration & dosage, RNA, Viral blood, Ribavirin administration & dosage, Sofosbuvir administration & dosage, Sulfonamides administration & dosage, Sustained Virologic Response, Treatment Outcome, Uracil administration & dosage, Uracil analogs & derivatives, Valine administration & dosage, Young Adult, Antiviral Agents administration & dosage, Hepacivirus isolation & purification, Hepatitis C, Chronic drug therapy
- Abstract
Background and Aims: Multiple direct-acting antiviral (DAA) regimens are available to treat HCV genotype 1 infection. However, comparative effectiveness from randomized controlled trials of DAA regimens is unavailable., Approach and Results: We conducted a pragmatic randomized controlled trial (NCT02786537) to compare the effectiveness of DAAs for HCV genotype 1a or 1b on viral response, safety, tolerability, and medication nonadherence. Adults with compensated liver disease, HCV genotype 1, not pregnant or breastfeeding, and with health insurance likely to cover ledipasvir/sofosbuvir (LDV/SOF) were recruited from 34 US viral hepatitis clinics. Participants were randomized (± ribavirin) to LDV/SOF, elbasvir/grazoprevir (EBR/GZR), and paritaprevir/ritonavir/ombitasvir+dasabuvir (PrOD; treatment arm stopped early). Primary outcomes included sustained viral response at 12 weeks (SVR12), clinician-recorded adverse events, patient-reported symptoms, and medication nonadherence. Between June 2016 and March 2018, 1,609 participants were randomized. Among 1,128 participants who received ≥1 dose of EBR/GZR or LDV/SOF (± ribavirin), SVR12 was 95.2% (95% CI, 92.8%-97.6%) and 97.4% (95% CI, 95.5%-99.2%), respectively, with a difference estimate of 2.2% (-0.5% to 4.7%), falling within the "equivalence" interval (-5% to 5%). While most (56%) participants experienced adverse events, few were serious (4.2%) or severe (1.8%). In the absence of ribavirin, discontinuations due to adverse events were rare. Patient-reported symptoms and medication nonadherence were similar. Study limitations were dropout due to insurance denial and loss to follow-up after treatment, limiting the ability to measure SVR12., Conclusions: This pragmatic trial demonstrated high SVR12 for participants treated with EBR/GZR and LDV/SOF with few adverse effects. Overall, the two regimens were equivalent in effectiveness. The results support current HCV guidelines that do not distinguish between ribavirin-free EBR/GZR and LDV/SOF., (© 2021 The Authors. Hepatology published by Wiley Periodicals LLC on behalf of American Association for the Study of Liver Diseases.)
- Published
- 2021
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173. The Type and Amount of Dietary Fat Affect Plasma Factor VIIc, Fibrinogen, and PAI-1 in Healthy Individuals and Individuals at High Cardiovascular Disease Risk: 2 Randomized Controlled Trials.
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Kris-Etherton PM, Stewart PW, Ginsberg HN, Tracy RP, Lefevre M, Elmer PJ, Berglund L, Ershow AG, Pearson TA, Ramakrishnan R, Holleran SF, Dennis BH, Champagne CM, and Karmally W
- Subjects
- Adult, Aged, Diet, Dietary Fats classification, Factor VII genetics, Female, Fibrinogen genetics, Gene Expression Regulation drug effects, Hemostasis, Humans, Male, Middle Aged, Plasminogen Activator Inhibitor 1 genetics, Risk Factors, Young Adult, Cardiovascular Diseases metabolism, Dietary Fats administration & dosage, Dietary Fats pharmacology, Factor VII metabolism, Fibrinogen metabolism, Plasminogen Activator Inhibitor 1 metabolism
- Abstract
Background: Factor VIIc, fibrinogen, and plasminogen activator inhibitor 1 (PAI-1) are cardiovascular disease (CVD) risk factors and are modulated, in part, by fat type and amount., Objective: We evaluated fat type and amount on the primary outcomes: factor VIIc, fibrinogen, and PAI-1., Methods: In the Dietary Effects on Lipoproteins and Thrombogenic Activity (DELTA) Trial, 2 controlled crossover feeding studies evaluated substituting carbohydrate or MUFAs for SFAs. Study 1: healthy participants (n = 103) were provided with (8 wk) an average American diet [AAD; designed to provide 37% of energy (%E) as fat, 16% SFA], a Step 1 diet (30%E fat, 9% SFA), and a diet low in SFA (Low-Sat; 26%E fat, 5% SFA). Study 2: participants (n = 85) at risk for CVD and metabolic syndrome (MetSyn) were provided with (7 wk) an AAD, a step 1 diet, and a high-MUFA diet (designed to provide 37%E fat, 8% SFA, 22% MUFA)., Results: Study 1: compared with AAD, the Step 1 and Low-Sat diets decreased mean factor VIIc by 1.8% and 2.6% (overall P = 0.0001), increased mean fibrinogen by 1.2% and 2.8% (P = 0.0141), and increased mean square root PAI-1 by 0.0% and 6.0% (P = 0.0037), respectively. Study 2: compared with AAD, the Step 1 and high-MUFA diets decreased mean factor VIIc by 4.1% and 3.2% (overall P < 0.0001), increased mean fibrinogen by 3.9% and 1.5% (P = 0.0083), and increased mean square-root PAI-1 by 2.0% and 5.8% (P = 0.1319), respectively., Conclusions: Replacing SFA with carbohydrate decreased factor VIIc and increased fibrinogen in healthy and metabolically unhealthy individuals and also increased PAI-1 in healthy subjects. Replacing SFA with MUFA decreased factor VIIc and increased fibrinogen but less than carbohydrate. Our results indicate an uncertain effect of replacing SFA with carbohydrate or MUFA on cardiometabolic risk because of small changes in hemostatic factors and directionally different responses to decreasing SFA. This trial was registered at https://clinicaltrials.gov/ct2/show/NCT00000538?term=NCT00000538&rank=1 as NCT00000538., (Copyright © The Author(s) on behalf of the American Society for Nutrition 2020.)
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- 2020
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174. Development and Reporting of Prediction Models: Guidance for Authors From Editors of Respiratory, Sleep, and Critical Care Journals.
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Leisman DE, Harhay MO, Lederer DJ, Abramson M, Adjei AA, Bakker J, Ballas ZK, Barreiro E, Bell SC, Bellomo R, Bernstein JA, Branson RD, Brusasco V, Chalmers JD, Chokroverty S, Citerio G, Collop NA, Cooke CR, Crapo JD, Donaldson G, Fitzgerald DA, Grainger E, Hale L, Herth FJ, Kochanek PM, Marks G, Moorman JR, Ost DE, Schatz M, Sheikh A, Smyth AR, Stewart I, Stewart PW, Swenson ER, Szymusiak R, Teboul JL, Vincent JL, Wedzicha JA, and Maslove DM
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- Bias, Critical Care standards, Decision Support Techniques, Humans, Prognosis, Reproducibility of Results, Critical Care organization & administration, Models, Statistical, Periodicals as Topic standards, Respiratory Tract Diseases epidemiology, Sleep Wake Disorders epidemiology
- Abstract
Prediction models aim to use available data to predict a health state or outcome that has not yet been observed. Prediction is primarily relevant to clinical practice, but is also used in research, and administration. While prediction modeling involves estimating the relationship between patient factors and outcomes, it is distinct from casual inference. Prediction modeling thus requires unique considerations for development, validation, and updating. This document represents an effort from editors at 31 respiratory, sleep, and critical care medicine journals to consolidate contemporary best practices and recommendations related to prediction study design, conduct, and reporting. Herein, we address issues commonly encountered in submissions to our various journals. Key topics include considerations for selecting predictor variables, operationalizing variables, dealing with missing data, the importance of appropriate validation, model performance measures and their interpretation, and good reporting practices. Supplemental discussion covers emerging topics such as model fairness, competing risks, pitfalls of "modifiable risk factors", measurement error, and risk for bias. This guidance is not meant to be overly prescriptive; we acknowledge that every study is different, and no set of rules will fit all cases. Additional best practices can be found in the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) guidelines, to which we refer readers for further details.
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- 2020
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175. A comprehensive assessment of patient reported symptom burden, medical comorbidities, and functional well being in patients initiating direct acting antiviral therapy for chronic hepatitis C: Results from a large US multi-center observational study.
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Evon DM, Stewart PW, Amador J, Serper M, Lok AS, Sterling RK, Sarkar S, Golin CE, Reeve BB, Nelson DR, Reau N, Lim JK, Reddy KR, Di Bisceglie AM, and Fried MW
- Subjects
- Adult, Aged, Aged, 80 and over, Cohort Studies, Comorbidity, Female, Hepatitis C, Chronic complications, Hepatitis C, Chronic virology, Humans, Insurance, Major Medical, International Normalized Ratio, Liver enzymology, Liver metabolism, Liver pathology, Liver Cirrhosis complications, Male, Mental Disorders complications, Middle Aged, RNA, Viral analysis, United States, Young Adult, Antiviral Agents therapeutic use, Hepatitis C, Chronic drug therapy, Patient Reported Outcome Measures
- Abstract
Background: Symptom burden, medical comorbidities, and functional well-being of patients with chronic hepatitis C virus (HCV) initiating direct acting antiviral (DAA) therapy in real-world clinical settings are not known. We characterized these patient-reported outcomes (PROs) among HCV-infected patients and explored associations with sociodemographic, liver disease, and psychiatric/substance abuse variables., Methods and Findings: PROP UP is a large US multicenter observational study that enrolled 1,600 patients with chronic HCV in 2016-2017. Data collected prior to initiating DAA therapy assessed the following PROs: number of medical comorbidities; neuropsychiatric, somatic, gastrointestinal symptoms (PROMIS surveys); overall symptom burden (Memorial Symptom Assessment Scale); and functional well-being (HCV-PRO). Candidate predictors included liver disease markers and patient-reported sociodemographic, psychiatric, and alcohol/drug use features. Predictive models were explored using a random selection of 700 participants; models were then validated with data from the remaining 900 participants. The cohort was 55% male, 39% non-white, 48% had cirrhosis (12% with advanced cirrhosis); 52% were disabled or unemployed; 63% were on public health insurance or uninsured; and over 40% had markers of psychiatric illness. The median number of medical comorbidities was 4 (range: 0-15), with sleep disorders, chronic pain, diabetes, joint pain and muscle aches being present in 20-50%. Fatigue, sleep disturbance, pain and neuropsychiatric symptoms were present in over 60% and gastrointestinal symptoms in 40-50%. In multivariable validation models, the strongest and most frequent predictors of worse PROs were disability, unemployment, and use of psychiatric medications, while liver markers generally were not., Conclusions: This large multi-center cohort study provides a comprehensive and contemporary assessment of the symptom burden and comorbid medical conditions in patients with HCV treated in real world settings. Pain, fatigue, and sleep disturbance were common and often severe. Sociodemographic and psychiatric markers were the most robust predictors of PROs. Future research that includes a rapidly changing population of HCV-infected individuals needs to evaluate how DAA therapy affects PROs and elucidate which symptoms resolve with viral eradication., Trial Registration: (Clinicaltrial.gov: NCT02601820)., Competing Interests: Donna M. Evon has received research funding from Gilead. Michael Fried has received research funding from and served as a consultant for AbbVie, BMS, Gilead, and Merck, and TARGET PharmaSolutions. Stock in TARGET PharmaSolutions is held in an independently managed trust. Anna S. Lok has received research support from AbbVie, BMS, Gilead, and Merck; and served as an advisor for Gilead. Richard K. Sterling has received research support from AbbVie, BMS, Gilead, Merck, and Roche and served as a consultant for Merck, Bayer, Salix, AbbVie, Gilead, Jansen, ViiV, Baxter, and Pfizer. Joseph K. Lim has received research support (paid to Yale University) and served as a consultant for Bristol-Myers Squibb and Gilead. Nancy Reau has received research funding (paid to Rush) from AbbVie and Intercept and has served as a consultant for AbbVie, Gilead, Merck, and BMS. Souvik Sarkar served on a Gilead and Abbvie Advisory Board. David R. Nelson has received research grant support from AbbVie, BMS, Gilead, Janssen, and Merck. K. Rajender Reddy is an Ad-Hoc Advisor to Gilead, BMS, Janssen, Merck, and Abbvie and has received research support from Gilead, BMS, Janssen, Merck, and AbbVie (paid to the University of Pennsylvania). Adrian M. Di Bisceglie has received research support from AbbVie, BMS and Gilead and has served on advisory boards for AbbVie, BMS and Merck. Paul Stewart has served as a consultant to TARGET PharmaSolutions. Jipcy Amador served as a biostatistics intern at TARGET PharmaSolutions in 2017. Carol E. Golin and Bryce Reeve declare that they have no conflict of interests to disclose. This does not alter our adherence to PLOS ONE policies on sharing data and materials.
- Published
- 2018
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176. Transporter-Mediated Alterations in Patients With NASH Increase Systemic and Hepatic Exposure to an OATP and MRP2 Substrate.
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Ali I, Slizgi JR, Kaullen JD, Ivanovic M, Niemi M, Stewart PW, Barritt AS 4th, and Brouwer KLR
- Abstract
The expression of hepatic transporters, including organic anion transporting polypeptides (OATPs) and multidrug resistance-associated proteins (MRPs), is altered in nonalcoholic steatohepatitis (NASH); however, functional data in humans are lacking. In this study,
99m Tc-mebrofenin (MEB) was used to evaluate OATP1B1/1B3 and MRP2 function in NASH patients. Healthy subjects (n = 14) and NASH patients (n = 7) were administered MEB (∼2.5 mCi). A population pharmacokinetic model was developed to describe systemic and hepatic MEB disposition. Study subjects were genotyped for SLCO1B1 variants. NASH increased systemic and hepatic exposure (median ± 2 SE, healthy vs. NASH) to MEB (AUC0-300,blood : 1,780 ± 242 vs. 2,440 ± 775 μCi*min/L, P = 0.006; AUC0-180,liver : 277 ± 36.9 vs. 433 ± 40.3 kcounts*min/sec, P < 0.0001) due to decreased biliary clearance (0.035 ± 0.008 vs. 0.017 ± 0.002 L/min, P = 0.0005) and decreased Vcentral (11.1 ± 0.57 vs. 6.32 ± 1.02 L, P < 0.0001). MEB hepatic CLuptake was reduced in NASH and also in healthy subjects with SLCO1B1 *15/*15 and *1A/*15 genotypes. The pharmacokinetics of drugs that are OATP1B1/1B3 and MRP2 substrates may be substantially altered in NASH., (© 2017, The American Society for Clinical Pharmacology and Therapeutics.)- Published
- 2017
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177. Cantharidin for the treatment of molluscum contagiosum: a prospective, double-blinded, placebo-controlled trial.
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Coloe Dosal J, Stewart PW, Lin JA, Williams CS, and Morrell DS
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- Cantharidin adverse effects, Child, Child, Preschool, Double-Blind Method, Enzyme Inhibitors adverse effects, Female, Follow-Up Studies, Humans, Male, North Carolina, Prospective Studies, Treatment Outcome, Cantharidin therapeutic use, Enzyme Inhibitors therapeutic use, Molluscum Contagiosum drug therapy
- Abstract
Our aim was to study the effects and safety of cantharidin in the treatment of molluscum contagiosum (MC), we conducted a prospective, double-blinded, placebo-controlled, randomized clinical trial to evaluate the safety and efficacy of topical cantharidin for treatment of pediatric MC in an academic ambulatory care center. Twenty-nine children aged 5-10 with a diagnosis of MC were enrolled to receive treatment with cantharidin or placebo. The main outcome measure was complete clearance of all molluscum lesions. In contrast to previous retrospective observational studies, the performance of cantharidin treatment over 2 months was not substantially better than the performance of placebo. The scope of follow-up was limited to five visits over 2 months of treatment. A longer follow-up period might have captured a greater effect of cantharidin. Over a 2 month period, the magnitude of the cantharidin treatment effects in the target population are, at best, not large. This study provided objective unbiased estimates of the magnitude of cantharidin treatment effects and provided important prospective safety data. Our subjects experienced minimal side effects when treated with cantharidin., (© 2012 Wiley Periodicals, Inc.)
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- 2014
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178. Monthly haemostatic factor variability in women and men.
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Hill AM, Stewart PW, Fung MK, Kris-Etherton PM, Ginsberg HN, Tracy RP, Pearson TA, Lefevre M, Reed RG, Elmer PJ, Holleran S, and Ershow AG
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- Adult, Aged, Estradiol blood, Female, Humans, Linear Models, Luteinizing Hormone blood, Male, Middle Aged, Progesterone blood, Sex Factors, Young Adult, Factor VII metabolism, Fibrinogen metabolism, Menstrual Cycle blood, Periodicity, Plasminogen Activator Inhibitor 1 blood, Postmenopause blood, Premenopause blood
- Abstract
Background: Hormonal status influences haemostatic factors including fibrinogen, factor VII and plasminogen activator inhibitor (PAI-1), and concentrations differ among men, premenopausal and postmenopausal women. This study examines how phases of the menstrual cycle influence variability of fibrinogen, factor VII and PAI-1., Design: We studied 103 subjects (39 premenopausal women, 18 postmenopausal women and 46 men) during three, randomized, 8-week energy- and nutrient-controlled experimental diets in the Dietary Effects on Lipids and Thrombogenic Activity (DELTA) Study. Fasting blood samples were collected weekly during the last 4 weeks of each diet period, and haemostatic factors were quantified. Two linear mixed-effects models were used for fibrinogen, factor VII and PAI-1: one to estimate and compare group-specific components of variance, and the other to estimate additional fixed effects representing cyclical functions of day of menstrual cycle in premenopausal women., Results: Systematic cyclical variation with day of menstrual cycle was observed for fibrinogen (P < 0.0001), factor VII (P = 0.0012) and PAI-1 (P = 0.0024) in premenopausal women. However, the amplitude of cycling was small relative to the total magnitude of intra-individual variability. In addition, the intra-individual variance and corresponding coefficient of variation observed in premenopausal women did not differ from postmenopausal women and men., Conclusions: The variability in haemostatic factors in premenopausal women is no greater than for postmenopausal women or men. Consequently, premenopausal women can be included in studies investigating haemostatic factor responses without controlling for stage of menstrual cycle., (© 2014 Stichting European Society for Clinical Investigation Journal Foundation.)
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- 2014
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179. Predictive value of initial triage vital signs for critically ill older adults.
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Lamantia MA, Stewart PW, Platts-Mills TF, Biese KJ, Forbach C, Zamora E, McCall BK, Shofer FS, Cairns CB, Busby-Whitehead J, and Kizer JS
- Abstract
Introduction: Triage of patients is critical to patient safety, yet no clear information exists as to the utility of initial vital signs in identifying critically ill older emergency department (ED) patients. The objective of this study is to evaluate a set of initial vital sign thresholds as predictors of severe illness and injury among older adults presenting to the ED., Methods: We reviewed all visits by patients aged 75 and older seen during 2007 at an academic ED serving a large community of older adults. Patients' charts were abstracted for demographic and clinical information including vital signs, via automated electronic methods. We used bivariate analysis to investigate the relationship between vital sign abnormalities and severe illness or injury, defined as intensive care unit (ICU) admission or ED death. In addition, we calculated likelihood ratios for normal and abnormal vital signs in predicting severe illness or injury., Results: 4,873 visits by patients aged 75 and above were made to the ED during 2007, and of these 3,848 had a complete set of triage vital signs. For these elderly patients, the sensitivity and specificity of an abnormal vital sign taken at triage for predicting death or admission to an ICU were 73% (66,81) and 50% (48,52) respectively (positive likelihood ratio 1.47 (1.30,1.60); negative likelihood ratio 0.54 (0.30,0.60)., Conclusion: Emergency provider assessment and triage scores that rely primarily on initial vital signs are likely to miss a substantial portion of critically ill older adults.
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- 2013
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180. The influence of sex, ethnicity, and CYP2B6 genotype on bupropion metabolism as an index of hepatic CYP2B6 activity in humans.
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Ilic K, Hawke RL, Thirumaran RK, Schuetz EG, Hull JH, Kashuba AD, Stewart PW, Lindley CM, and Chen ML
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- Administration, Oral, Adolescent, Adult, Black or African American genetics, Antidepressive Agents administration & dosage, Antidepressive Agents pharmacokinetics, Aryl Hydrocarbon Hydroxylases genetics, Biotransformation, Bupropion administration & dosage, Bupropion pharmacokinetics, Cytochrome P-450 CYP2B6, Delayed-Action Preparations, Female, Genotype, Hispanic or Latino genetics, Humans, Linear Models, Male, Middle Aged, Oxidoreductases, N-Demethylating genetics, Pharmacogenetics, Phenotype, Polymorphism, Genetic, Sex Factors, Substrate Specificity, White People genetics, Young Adult, Antidepressive Agents blood, Aryl Hydrocarbon Hydroxylases metabolism, Bupropion blood, Ethnicity genetics, Liver enzymology, Oxidoreductases, N-Demethylating metabolism
- Abstract
The effects of sex, ethnicity, and genetic polymorphism on hepatic CYP2B6 (cytochrome P450 2B6) expression and activity were previously demonstrated in vitro. Race/ethnic differences in CYP2B6 genotype and phenotype were observed only in women. To identify important covariates associated with interindividual variation in CYP2B6 activity in vivo, we evaluated these effects in healthy volunteers using bupropion (Wellbutrin SR GlaxoSmithKline, Research Triangle Park, NC) as a CYP2B6 probe substrate. A fixed 150-mg oral sustained-release dose of bupropion was administered to 100 healthy volunteers comprising four sex/ethnicity cohorts (n = 25 each): Caucasian men and Caucasian, African American, and Hispanic women. Blood samples were obtained at 0 and 6 hours postdose for the measurement of serum bupropion (BU) and hydroxybupropion (HB) concentrations. Whole blood was obtained at baseline for CYP2B6 genotyping. To characterize the relationship between CYP2B6 activity and ethnicity, sex, and genotype when accounting for serum BU concentrations (dose-adjusted log(10)-transformed), analysis of covariance model was fitted in which the dependent variable was CYP2B6 activity represented as the log(10)-transformed, metabolic ratio of HB to BU concentrations. Several CYP2B6 polymorphisms were associated with CYP2B6 activity. Evidence of dependence of CYP2B6 activity on ethnicity or genotype-by-ethnicity interactions was not detected in women. These results suggest that CYP2B6 genotype is the most important patient variable for predicting the level of CYP2B6 activity in women, when measured by the metabolism of bupropion. The bupropion metabolic ratio appears to detect known differences in CYP2B6 activity associated with genetic polymorphism, across different ethnic groups. Prospective studies will be needed to validate the use of bupropion as a probe substrate for clinical use.
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- 2013
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181. Effects of uridine diphosphate glucuronosyltransferase 2B7 and 1A7 pharmacogenomics and patient clinical parameters on steady-state mycophenolic acid pharmacokinetics in glomerulonephritis.
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Joy MS, Boyette T, Hu Y, Wang J, La M, Hogan SL, Stewart PW, Falk RJ, Dooley MA, and Smith PC
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- ATP Binding Cassette Transporter, Subfamily B, ATP Binding Cassette Transporter, Subfamily B, Member 1 genetics, Adult, Aged, Biomarkers blood, Creatinine blood, Enzyme Inhibitors blood, Female, Genotype, Humans, Linear Models, Lupus Nephritis genetics, Male, Middle Aged, Mycophenolic Acid blood, Polymorphism, Genetic, UDP-Glucuronosyltransferase 1A9, Vasculitis genetics, Vasculitis immunology, Antibodies, Antineutrophil Cytoplasmic blood, Enzyme Inhibitors pharmacokinetics, Glucuronosyltransferase genetics, Lupus Nephritis drug therapy, Lupus Nephritis enzymology, Mycophenolic Acid pharmacokinetics, Vasculitis drug therapy, Vasculitis enzymology
- Abstract
Purpose: The role of pharmacogenomics, clinical and demographic parameters in pharmacokinetic predictions was evaluated in patients receiving mycophenolic acid (MPA)., Methods: A cohort study design of patients with glomerulonephritis secondary to lupus nephritis and anti-neutrophil cytoplasmic antibody (ANCA) vasculitis was employed. Forty-six patients with lupus nephritis and ANCA vasculitis who were receiving MPA were recruited from the nephrology clinic. The study assessed the relative single and combined roles of genomic, clinical, and demographic characteristics on pharmacokinetic parameters using general linear models. The study focused on polymorphisms in UGT1A7, UGT2B7, and ABCB1/MDR1; all of which have limited data available concerning MPA pharmacokinetics. All patients had pharmacokinetic assessments for MPA and glucuronide metabolites (MPAG, AcMPAG). Genotyping was performed for known variants of UGTs (UGT1A9, UGT1A7, UGT2B7), and multidrug resistance protein (ABCB1/MDR1), involved in MPA disposition. Analyses included univariate and multivariate linear modeling., Results: In univariate analyses, UGT2B7 heterozygosity (coefficient 0.3508; R (2)=0.0873) and UGT1A7 heterozygosity (coefficient 0.3778; R (2)=0.0966) predicted increased apparent oral clearance of MPA. UGT1A7 heterozygosity (coefficient -0.4647; R (2) 0.0897) predicted lower MPA trough concentrations. In multivariate assessments, higher urinary protein excretion, lower serum creatinine, and increased weight predicted greater apparent oral clearance of MPA (p < 0.0001). White race and higher serum creatinine predicted higher MPA trough concentrations (p < 0.0001). Higher exposure to MPA was predicted by decreased urinary protein excretion and increased serum creatinine., Conclusions: Clinical and demographic parameters were 2-4 times more important in MPA disposition than genotypes and explained 30-40% of the pharmacokinetic parameters.
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- 2010
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182. Inhaled versus systemic antibiotics and airway inflammation in children with cystic fibrosis and Pseudomonas.
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Noah TL, Ivins SS, Abode KA, Stewart PW, Michelson PH, Harris WT, Henry MM, and Leigh MW
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- Administration, Inhalation, Bronchoalveolar Lavage Fluid, Child, Child, Preschool, Cystic Fibrosis microbiology, Female, Humans, Infant, Infusions, Intravenous, Male, Pneumonia, Bacterial immunology, Pneumonia, Bacterial microbiology, Anti-Bacterial Agents administration & dosage, Cystic Fibrosis immunology, Pneumonia, Bacterial drug therapy, Pseudomonas Infections drug therapy
- Abstract
Rationale: Inhaled tobramycin has been shown to transiently clear Pseudomonas from lower airways in early cystic fibrosis (CF), but does not markedly reduce lung inflammation, a key factor in disease progression., Objective: Test the hypothesis that systemic antibiotics are more effective than inhaled antibiotics for reducing lower airways inflammation., Methods: Clinically stable CF children with recent Pseudomonas were randomized to receive 4 weeks of inhaled tobramycin or 2 weeks of systemic antibiotics (intravenous ceftazidime and tobramycin). Bronchoalveolar lavage fluid was obtained just before and 4-6 weeks after treatment. The primary outcome was change in % neutrophils in lavage fluid., Results: Fifteen subjects (inhaled = 6, systemic = 9) completed the protocol. Three Systemic Group subjects could not have central venous access established and were treated with oral ciprofloxacin (plus inhaled tobramycin) for 2 weeks as an alternative "systemic" regimen, per protocol. Groups were well matched in age, markers of disease severity, and initial % neutrophils. The Systemic Group showed a modest median change in percent neutrophils (-7%) which was not statistically significant compared to inhaled (+5.4%, P = 0.07). However, the Systemic Group had significantly greater reductions in total cells (-50% vs. -3%, P < 0.01) and neutrophils (-74% vs. -10%, P = 0.02) per ml lavage fluid. Both groups had reduced bacterial quantity after treatment, but there was no significant difference between groups., Conclusions: In clinically stable children with CF, systemic antibiotics result in greater short-term reduction in lower airways inflammation than inhaled antibiotics.
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- 2010
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183. The relationship between prenatal PCB exposure and intelligence (IQ) in 9-year-old children.
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Stewart PW, Lonky E, Reihman J, Pagano J, Gump BB, and Darvill T
- Subjects
- Child, Confounding Factors, Epidemiologic, Dose-Response Relationship, Drug, Environmental Exposure, Female, Humans, Pregnancy, Risk Factors, Social Class, United States, Environmental Pollutants toxicity, Intelligence drug effects, Polychlorinated Biphenyls toxicity, Prenatal Exposure Delayed Effects
- Abstract
Background: Several epidemiologic studies have demonstrated relationships between prenatal exposure to polychlorinated biphenyls (PCBs) and modest cognitive impairments in infancy and early childhood. However, few studies have followed cohorts of exposed children long enough to examine the possible impact of prenatal PCB exposure on psychometric intelligence in later childhood. Of the few studies that have done so, one in the Great Lakes region of the United States reported impaired IQ in children prenatally exposed to PCBs, whereas another found no association., Objectives: This study was designed to determine whether environmental exposure to PCBs predicts lower IQ in school-age children in the Great Lakes region of the northeastern United States., Methods: We measured prenatal exposure to PCBs and IQ at 9 years of age in 156 subjects from Oswego, New York. We also measured > 50 potential predictors of intelligence in children, including repeated measures of the home environment [Home Observation for Measurement of the Environment (HOME)], socioeconomic status (SES), parental IQ, alcohol/cigarette use, neonatal risk factors, and nutrition., Results: For each 1-ng/g (wet weight) increase in PCBs in placental tissue, Full Scale IQ dropped by three points (p = 0.02), and Verbal IQ dropped by four points (p = 0.003). The median PCB level was 1.50 ng/g, with a lower quartile of 1.00 ng/g and an upper quartile of 2.06 ng/g. Moreover, this association was significant after controlling for many potential confounders, including prenatal exposure to methylmercury, dichlorodiphenyldichloroethylene, hexachlorobenzene, and lead., Conclusions: These results, in combination with similar results obtained from a similar study in the Great Lakes conducted 10 years earlier, indicate that prenatal PCB exposure in the Great Lakes region is associated with lower IQ in children.
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- 2008
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184. Comparison of monounsaturated fat with carbohydrates as a replacement for saturated fat in subjects with a high metabolic risk profile: studies in the fasting and postprandial states.
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Berglund L, Lefevre M, Ginsberg HN, Kris-Etherton PM, Elmer PJ, Stewart PW, Ershow A, Pearson TA, Dennis BH, Roheim PS, Ramakrishnan R, Reed R, Stewart K, and Phillips KM
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- Adult, Apolipoprotein A-I blood, Apolipoproteins B blood, Blood Glucose metabolism, Cholesterol blood, Cross-Over Studies, Dietary Carbohydrates metabolism, Dietary Fats metabolism, Dietary Fats, Unsaturated metabolism, Double-Blind Method, Female, Humans, Insulin blood, Lipoprotein(a) blood, Male, Middle Aged, Postprandial Period, Triglycerides blood, Uric Acid blood, Dietary Carbohydrates administration & dosage, Dietary Fats administration & dosage, Dietary Fats, Unsaturated administration & dosage
- Abstract
Background: In subjects with a high prevalence of metabolic risk abnormalities, the preferred replacement for saturated fat is unresolved., Objective: The objective was to study whether carbohydrate or monounsaturated fat is a preferred replacement for saturated fat., Design: Fifty-two men and 33 women, selected to have any combination of HDL cholesterol < or = 30th percentile, triacylglycerol > or = 70th percentile, or insulin > or = 70th percentile, were enrolled in a 3-period, 7-wk randomized crossover study. The subjects consumed an average American diet (AAD; 36% of energy from fat) and 2 additional diets in which 7% of energy from saturated fat was replaced with either carbohydrate (CHO diet) or monounsaturated fatty acids (MUFA diet)., Results: Relative to the AAD, LDL cholesterol was lower with both the CHO (-7.0%) and MUFA (-6.3%) diets, whereas the difference in HDL cholesterol was smaller during the MUFA diet (-4.3%) than during the CHO diet (-7.2%). Plasma triacylglycerols tended to be lower with the MUFA diet, but were significantly higher with the CHO diet. Although dietary lipid responses varied on the basis of baseline lipid profiles, the response to diet did not differ between subjects with or without the metabolic syndrome or with or without insulin resistance. Postprandial triacylglycerol concentrations did not differ significantly between the diets. Lipoprotein(a) concentrations increased with both the CHO (20%) and MUFA (11%) diets relative to the AAD., Conclusions: In the study population, who were at increased risk of coronary artery disease, MUFA provided a greater reduction in risk as a replacement for saturated fat than did carbohydrate.
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- 2007
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185. Defining cancer cachexia in head and neck squamous cell carcinoma.
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Richey LM, George JR, Couch ME, Kanapkey BK, Yin X, Cannon T, Stewart PW, Weissler MC, and Shores CG
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- Aged, Cachexia etiology, Cachexia metabolism, Carcinoma, Squamous Cell pathology, Cytokines blood, Cytokines genetics, Cytokines metabolism, Female, Head and Neck Neoplasms pathology, Humans, Interleukin-6 blood, Interleukin-6 genetics, Male, Middle Aged, Quality of Life, RNA, Messenger analysis, RNA, Messenger metabolism, Cachexia diagnosis, Carcinoma, Squamous Cell complications, Head and Neck Neoplasms complications, Interleukin-6 metabolism
- Abstract
Purpose: Cancer cachexia is a devastating and understudied illness in patients with head and neck squamous cell carcinoma (HNSCC). The primary objective was to identify clinical characteristics and serum levels of cytokines and cachexia-related factors in patients with HNSCC. The secondary objective was to detect the occurrence of cytokine and cachexia-related factor gene expression in HNSCC tumors., Experimental Design: For the primary objective, cross-sectional data were obtained from prospectively recruited patients identified as cachexia cases and matching cachexia-free controls. For the secondary objective, a retrospective cohort design with matched controls was used., Results: Clinical characteristics associated with cancer cachexia in HNSCC were T(4) status (P = 0.01), increased C-reactive protein (P = 0.01), and decreased hemoglobin (P < 0.01). Exploratory multiplex analysis of serum cytokine levels found increased interleukin (IL)-6 (P = 0.04). A highly sensitive ELISA confirmed the multiplex result for increased IL-6 in cachectic patients (P = 0.02). Quality of life was substantially reduced in patients with cachexia compared with noncachectic patients (P < 0.01). All tumors of HNSCC patients both with and without cachexia expressed RNA for each cytokine tested and the cachexia factor lipid-mobilizing factor. There were no statistically significant differences between the cytokine and cachexia factor RNA expression of cachectic and noncachectic patients (each P > 0.05). No tumors expressed the cachexia factor proteolysis-inducing factor., Conclusion: We have identified clinical characteristics and pathophysiologic mechanisms associated with cancer cachexia in a carefully defined population of patients with HNSCC. The data suggest that the acute-phase response and elevated IL-6 are associated with this complex disease state. We therefore hypothesize that IL-6 may represent an important therapeutic target for HNSCC patients with cancer cachexia.
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- 2007
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186. Antiretroviral drug exposure in the female genital tract: implications for oral pre- and post-exposure prophylaxis.
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Dumond JB, Yeh RF, Patterson KB, Corbett AH, Jung BH, Rezk NL, Bridges AS, Stewart PW, Cohen MS, and Kashuba AD
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- Adenine administration & dosage, Adenine analogs & derivatives, Adenine blood, Adenine pharmacokinetics, Administration, Oral, Adult, Alkynes, Anti-Retroviral Agents blood, Anti-Retroviral Agents pharmacokinetics, Atazanavir Sulfate, Benzoxazines administration & dosage, Benzoxazines blood, Benzoxazines pharmacokinetics, Cyclopropanes, Deoxycytidine administration & dosage, Deoxycytidine analogs & derivatives, Deoxycytidine blood, Deoxycytidine pharmacokinetics, Drug Therapy, Combination, Emtricitabine, Female, HIV Infections blood, HIV Protease Inhibitors administration & dosage, HIV Protease Inhibitors blood, HIV Protease Inhibitors pharmacokinetics, Humans, Lamivudine administration & dosage, Lamivudine blood, Lamivudine pharmacokinetics, Lopinavir, Oligopeptides administration & dosage, Oligopeptides blood, Oligopeptides pharmacokinetics, Organophosphonates administration & dosage, Organophosphonates blood, Organophosphonates pharmacokinetics, Pyridines administration & dosage, Pyridines blood, Pyridines pharmacokinetics, Pyrimidinones administration & dosage, Pyrimidinones blood, Pyrimidinones pharmacokinetics, Reverse Transcriptase Inhibitors administration & dosage, Reverse Transcriptase Inhibitors blood, Reverse Transcriptase Inhibitors pharmacokinetics, Tenofovir, Zidovudine administration & dosage, Zidovudine blood, Zidovudine pharmacokinetics, Anti-Retroviral Agents administration & dosage, Genitalia, Female metabolism, HIV Infections drug therapy
- Abstract
Objectives: To describe first dose and steady state antiretroviral drug exposure in the female genital tract., Design: Non-blinded, single center, open-label pharmacokinetic study in HIV-infected women., Method: Twenty-seven women initiating combination antiretroviral therapy underwent comprehensive blood plasma and cervicovaginal fluid sampling for drug concentrations during the first dose of antiretroviral therapy and at steady-state. Drug concentrations were measured by validated HPLC/UV or HPLC-MS/MS methods. Pharmacokinetic parameters were estimated for 11 drugs by non-compartmental analysis. Descriptive statistics and 95% confidence intervals were generated using Intercooled STATA Release 8.0 (Stata Corporation, College Station, Texas, USA)., Results: For all antiretroviral drugs, genital tract concentrations were detected rapidly after the first dose. Drugs were stratified according to the genital tract concentrations achieved relative to blood plasma. Median rank order of highest to lowest genital tract concentrations relative to blood plasma at steady state were: lamivudine (concentrations achieved were 411% greater than blood plasma), emtricitabine (395%), zidovudine (235%) tenofovir (75%), ritonavir (26%), didanosine (21%), atazanavir (18%), lopinavir (8%), abacavir (8%), stavudine (5%), and efavirenz (0.4%)., Conclusions: This is the first study to comprehensively evaluate antiretroviral drug exposure in the female genital tract. These findings support the use of lamivudine, zidovudine, tenofovir and emtricitabine as excellent pre-exposure/post-exposure prophylaxis (PrEP/PEP) candidates. Atazanavir and lopinavir might be useful agents for these applications due to favorable therapeutic indices, despite lower genital tract concentrations. Agents such as stavudine, abacavir, and efavirenz that achieve genital tract exposures less than 10% of blood plasma are less attractive PrEP/PEP candidates.
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- 2007
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187. Amplified transmission of HIV-1: comparison of HIV-1 concentrations in semen and blood during acute and chronic infection.
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Pilcher CD, Joaki G, Hoffman IF, Martinson FE, Mapanje C, Stewart PW, Powers KA, Galvin S, Chilongozi D, Gama S, Price MA, Fiscus SA, and Cohen MS
- Subjects
- Acute Disease, Adolescent, Adult, Chronic Disease, Disease Progression, Epidemiologic Methods, HIV Infections transmission, Humans, Male, Middle Aged, RNA, Viral analysis, RNA, Viral blood, Viral Load, Viremia virology, Virus Shedding, HIV Infections virology, HIV-1 isolation & purification, Semen virology
- Abstract
Objectives: This study was conducted to compare viral dynamics in blood and semen between subjects with antibody negative, acute HIV-1 infection and other subjects with later stages of infection., Design: A prospective cohort study was embedded within a cross-sectional study of HIV screening in a Lilongwe, Malawi STD clinic., Methods: Blood samples from HIV antibody negative or indeterminate volunteers were used to detect HIV RNA in plasma using a pooling strategy. Blood and seminal plasma HIV-1 RNA concentrations were measured over 16 weeks., Results: Sixteen men with acute HIV infection and 25 men with chronic HIV infection were studied. Blood viral load in subjects with acute HIV infection was highest about 17 days after infection (mean +/- SE, 6.9 +/- 0.5 log10 copies/ml), while semen viral load peaked about 30 days after infection (4.5 +/- 0.4 log10 copies/ml). Semen viral load declined by 1.7 log10 to a nadir by week 10 of HIV infection. Semen and blood viral loads were more stable in chronically infected subjects over 16 weeks. Higher semen levels of HIV RNA were noted in subjects with low CD4 cell counts., Conclusions: These results provide a biological explanation for reported increases in HIV transmission during the very early (acute) and late stages of infection. Recognizing temporal differences in HIV shedding in the genital tract is important in the development of effective HIV prevention strategies.
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- 2007
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188. Sex and menopausal status influence human dietary requirements for the nutrient choline.
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Fischer LM, daCosta KA, Kwock L, Stewart PW, Lu TS, Stabler SP, Allen RH, and Zeisel SH
- Subjects
- Adolescent, Adult, Aged, Choline metabolism, Choline pharmacokinetics, Choline Deficiency metabolism, Dose-Response Relationship, Drug, Fatty Liver metabolism, Female, Folic Acid administration & dosage, Folic Acid pharmacology, Humans, Male, Middle Aged, Muscle, Skeletal enzymology, Muscle, Skeletal metabolism, Nutrition Policy, Phosphatidylcholines metabolism, Sex Factors, Choline administration & dosage, Choline Deficiency complications, Fatty Liver etiology, Menopause physiology, Muscle, Skeletal pathology, Nutritional Requirements
- Abstract
Background: Although humans require dietary choline for methyl donation, membrane function, and neurotransmission, choline can also be derived from the de novo synthesis of phosphatidylcholine, which is up-regulated by estrogen. A recommended Adequate Intake (AI) exists for choline; however, an Estimated Average Requirement has not been set because of a lack of sufficient human data., Objective: The objective of the study was to evaluate the dietary requirements for choline in healthy men and women and to investigate the clinical sequelae of choline deficiency., Design: Fifty-seven adult subjects (26 men, 16 premenopausal women, 15 postmenopausal women) were fed a diet containing 550 mg choline x 70 kg(-1) x d(-1) for 10 d followed by <50 mg choline x 70 kg(-1) x d(-1) with or without a folic acid supplement (400 microg/d per randomization) for up to 42 d. Subjects who developed organ dysfunction during this diet had normal organ function restored after incremental amounts of choline were added back to the diet. Blood and urine were monitored for signs of toxicity and metabolite concentrations, and liver fat was assessed by using magnetic resonance imaging., Results: When deprived of dietary choline, 77% of men and 80% of postmenopausal women developed fatty liver or muscle damage, whereas only 44% of premenopausal women developed such signs of organ dysfunction. Moreover, 6 men developed these signs while consuming 550 mg choline x 70 kg(-1) x d(-1), the AI for choline. Folic acid supplementation did not alter the subjects' response., Conclusion: Subject characteristics (eg, menopausal status) modulated the dietary requirement for choline, and a daily intake at the current AI was not sufficient to prevent organ dysfunction in 19 of the subjects.
- Published
- 2007
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189. Response inhibition during Differential Reinforcement of Low Rates (DRL) schedules may be sensitive to low-level polychlorinated biphenyl, methylmercury, and lead exposure in children.
- Author
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Stewart PW, Sargent DM, Reihman J, Gump BB, Lonky E, Darvill T, Hicks H, and Pagano J
- Subjects
- Analysis of Variance, Child, Child, Preschool, Dose-Response Relationship, Drug, Female, Humans, Infant, Infant, Newborn, Learning drug effects, Linear Models, Male, Pregnancy, Prenatal Exposure Delayed Effects psychology, Reinforcement Schedule, Reinforcement, Psychology, Environmental Pollutants poisoning, Lead, Methylmercury Compounds poisoning, Polychlorinated Biphenyls poisoning, Prenatal Exposure Delayed Effects chemically induced
- Abstract
Background: Animal studies have shown that exposure to common, low-level environmental contaminants [e.g., polychlorinated biphenyls (PCBs), lead] causes excessive and inappropriate responding on intermittent reinforcement schedules. The Differential Reinforcement of Low Rates task (DRL) has been shown to be especially sensitive to low-level PCB exposure in monkeys., Objectives: We investigated the relationships between prenatal PCB and postnatal Pb exposure performance on a DRL schedule in children. We predicted that a) prenatal PCB exposure would reduce interresponse times (IRTs) and reinforcements earned, and b) postnatal Pb exposure would reduce IRTs and reinforcements earned., Methods: We tested 167 children on a DRL20 (20 sec) reinforcement schedule, and recorded IRTs and the number of reinforced responses across the session. We measured prenatal PCB exposure (cord blood), methylmercury (MeHg) (maternal hair), and postnatal Pb exposure (venous blood), and > 50 potentially confounding variables., Results: Results indicated impaired performance in children exposed to PCBs, MeHg, and Pb. Children prenatally exposed to PCBs responded excessively, with significantly lower IRTs and fewer reinforcers earned across the session. In addition, exposure to either MeHg or Pb predicted statistically significant impairments of a similar magnitude to those for PCBs, and the associated impairments of all three contaminants (PCB, MeHg, and Pb) were statistically independent of one another., Conclusions: These results, taken with animal literature, argue the high sensitivity of DRL performance to low-level PCB, MeHg, and Pb exposure. Future research should employ behavioral tasks in children, such as DRL, that have been demonstrably sensitive to low-level PCB, MeHg, and Pb exposure in animals.
- Published
- 2006
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190. Variation in oral clearance of saquinavir is predicted by CYP3A5*1 genotype but not by enterocyte content of cytochrome P450 3A5.
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Mouly SJ, Matheny C, Paine MF, Smith G, Lamba J, Lamba V, Pusek SN, Schuetz EG, Stewart PW, and Watkins PB
- Subjects
- ATP Binding Cassette Transporter, Subfamily B, Member 1 genetics, ATP Binding Cassette Transporter, Subfamily B, Member 1 metabolism, Administration, Oral, Adult, Area Under Curve, Beverages, Biological Availability, Carbon Radioisotopes, Citrus, Cross-Over Studies, Cytochrome P-450 CYP3A, Cytochrome P-450 Enzyme System metabolism, Dose-Response Relationship, Drug, Enterocytes metabolism, Female, Gene Expression drug effects, Genotype, HIV Protease Inhibitors administration & dosage, HIV Protease Inhibitors pharmacokinetics, Half-Life, Hepatocytes enzymology, Hepatocytes metabolism, Humans, Intestinal Mucosa metabolism, Intestines enzymology, Male, Metabolic Clearance Rate, Saquinavir administration & dosage, Saquinavir blood, Cytochrome P-450 Enzyme System genetics, Enterocytes enzymology, Polymorphism, Genetic, Saquinavir pharmacokinetics
- Abstract
Objective: Saquinavir, a widely prescribed human immunodeficiency virus 1 protease inhibitor, has a low and variable oral bioavailability that has been attributed to extensive first-pass extraction mediated by hepatic or intestinal cytochrome P450 (CYP) 3A4 and intestinal P-glycoprotein (P-gp). The polymorphic CYP3A5 has also been shown to influence the saquinavir metabolite/parent urinary ratio, suggesting a role for CYP3A5., Methods: Twenty healthy subjects received a single oral dose of saquinavir (600 mg) with water (control) and, on a separate occasion, with Seville orange juice (a selective intestinal CYP3A4/5 inhibitor). Hepatic CYP3A4 activity was evaluated by use of the erythromycin breath test. Duodenal biopsy specimens were used to assess relative intestinal CYP3A4 and CYP3A5 protein contents. Relative P-gp content was also assessed in the biopsy specimens and in lymphocytes. Genetic polymorphisms in MDR1 (in exon 21 and 26), CYP3A5 (*1 and *3), and CYP3A4*1B were identified by direct sequencing. Saquinavir plasma concentrations were measured by tandem liquid chromatography-mass spectrometry. Pharmacokinetic parameter estimates (maximum concentration, time to reach maximum concentration, area under the concentration-time curve, apparent oral clearance [CL/F]) were computed by standard noncompartmental methods. Stepwise multiple regression analysis was used to identify the hepatic or intestinal variables that predicted variation in saquinavir pharmacokinetic measures., Results: Baseline saquinavir CL/F was not correlated with liver CYP3A4 activity (the erythromycin breath test result), intestinal CYP3A4 content, or intestinal P-gp content (r(2) = 0.08, 0.08, and 0.007, respectively; P > .2). MDR1 genotype and lymphocyte P-gp content were also not predictive. Among the 6 subjects expressing intestinal CYP3A5, the mean saquinavir CL/F was almost twice as high as for the 14 nonexpressors (36.7 L/h [95% confidence interval (CI), 18.7-54.6 L/h] and 19.3 L/h [95% CI, 11.2-27.4 L/h], respectively; P = .03). However, among the 6 CYP3A5 expressors, there was an unexpected negative correlation between CL/F and intestinal CYP3A5 content (r(2) = 0.58, P = .05). Seville orange juice decreased the mean CL/F in all 20 subjects from 24.5 L/h (95% CI, 16.7-32.3 L/h) to 14.7 L/h (95% CI, 8.4-20.6 L/h) (P = .05). The effect size did not appear to be influenced by CYP3A5 expression., Conclusions: The CYP3A5*1 genotype is associated with increased saquinavir CL/F. This does not appear to reflect intestinal CYP3A5 expression and presumably reflects the contribution of hepatic CYP3A5. The interaction with Seville orange juice in subjects not expressing CYP3A5 supports a role for intestinal CYP3A4. However, the modest nature of the interaction, combined with the inability to detect a correlation between CL/F and CYP3A4 enterocyte content, supports our recent in vitro work suggesting a smaller contribution of intestinal CYP3A4 than has been assumed.
- Published
- 2005
- Full Text
- View/download PDF
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