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1.  Vitamin D3 supplementation increases fibroblast growth factor-23 in HIV-infected youth treated with tenofovir disoproxil fumarate 
Antiviral therapy  2014;19(6):613-618.
Background
Tenofovir (TDF) is associated with phosphaturia and elevated 1,25 dihydroxy vitamin D (1,25-OH(2)D). Fibroblast growth factor 23 (FGF23) causes phosphaturia and increases in response to elevated 1,25-OH(2)D. Vitamin D binding protein (VDBP) binds to 1,25-OH(2)D, decreasing its biologic activity, and is elevated in persons with higher plasma tenofovir concentrations. We compared FGF23 and VDBP before and after vitamin D3 (VITD) supplementation in youth treated with combination antiretroviral therapy (cART) containing or not containing TDF.
Methods
A randomized controlled trial in HIV+ youth ages 18–25 years enrolled participants based on cART treatment with TDF (TDF, N=118) or without TDF (no-TDF, N=85) and randomized within those groups to VITD (50,000 IU every four weeks) or placebo (PL). We measured FGF23 and VDBP and calculated free 1,25-OH(2)D at baseline and week 12, and compared changes by TDF treatment and VITD randomized group.
Results
At baseline, serum FGF23 concentration showed a quadratic relationship with 1,25-OH(2)D most pronounced in the TDF group. At week 12, total and free 1,25-OH(2)D increased in the VITD but not PL groups, independent of TDF use. FGF23 increased in the TDF group receiving VITD, but there was no FGF23 change in the no-TDF group receiving VITD or the PL groups. The adjusted mean change in FGF23 from baseline to week 12 was +7.7 pg/mL in the TDF/VITD group, compared to −1.7 (no-TDF/VITD, p=0.010); −1.3 (TDF/PL, p=0.006); and +1.1 (no-TDF/PL, p=0.035).
Conclusions
These results suggest that TDF-containing cART may alter the FGF23 response to vitamin D supplementation in HIV-infected youth.
doi:10.3851/IMP2755
PMCID: PMC4135028  PMID: 24535626
2.  Immunogenicity of Licensed Influenza A (H1N1) 2009 Monovalent Vaccines in HIV-Infected Children and Youth 
Background
With the emergence of pandemic influenza A (pH1N1) in 2009, children and youth infected with human immunodeficiency virus (HIV) were vulnerable because of immunologic impairment and the greater virulence of this infection in young persons.
Methods
A multicenter study of the immunogenicity of 3 licensed influenza A (H1N1) monovalent vaccines (1 live attenuated and 2 inactivated) was conducted in children and youth with perinatal HIV infection, most of whom were receiving ≥3 antiretroviral drugs, had CD4% ≥15, and plasma HIV RNA levels <400 copies/mL. Serum hemagglutinin inhibition assay (HAI) antibody levels were measured and correlated with baseline demographic and clinical variables.
Results
One hundred forty-nine subjects were enrolled at 26 sites in the United States and Puerto Rico. Over 40% had baseline HAI titers ≥40. For subjects aged 6 months to <10 years, 79% and 68%, respectively, achieved a ≥40- and ≥4-fold rise in HAI titers after the second dose of vaccine. Three weeks after a single immunization with an inactivated vaccine, similar immunogenicity results were achieved in youth aged 10–24 years. With multivariable analysis, only Hispanic ethnicity and CD4% ≥15 were associated with achieving both HAI titer ≥40- and ≥4-fold rise in titer.
Conclusions
Although licensed pH1N1 vaccines produced HAI titers that were considered to be protective in the majority of HIV-infected children and youth, the proportion with titers ≥40- and ≥4-fold rise in titer was lower than expected for children without HIV infection. Vaccine immunogenicity was lower in HIV-infected children and youth with evidence of immune suppression.
doi:10.1093/jpids/pit040
PMCID: PMC3869470  PMID: 24363932
3.  Safety and Immunogenicity of 2009 Pandemic H1N1 Influenza Vaccination in Perinatally HIV-1–Infected Children, Adolescents, and Young Adults 
The Journal of Infectious Diseases  2012;206(3):421-430.
Background. The safety and immunogenicity of high-dose pandemic H1N1 (pH1N1) vaccination in perinatally human immunodeficiency virus type 1 (HIV-1)–infected children, adolescents, and young adults are unknown.
Methods. Two 30-μg doses of 2009 Novartis pH1N1 monovalent vaccine (Fluvirin) were administered 21–28 days apart to perinatally HIV-1–infected children, adolescents, and young adults. Antibodies were measured by hemagglutination inhibition (HAI) assay at baseline, 21–28 days after first vaccination, 7–13 days after the second vaccination, and 7 months after the first vaccination.
Results. Among the 155 participants, 54 were aged 4–8 years, 51 were aged 9–17 years, and 50 were aged 18–24 years. After 2 doses of Fluvirin, seroresponse (≥4-fold rise in HAI titers) was demonstrated in 79.6%, 84.8%, and 83% of participants in the aforementioned age groups, respectively, and seroprotection (HAI titers ≥40) was shown in 79.6%, 82.6%, and 85.1%, respectively. Of those lacking seroresponse (n = 43) or seroprotection (n = 37) after the first vaccination, 46.5% and 40.5% achieved seroresponse or seroprotection, respectively, after the second vaccination. Among participants who lacked seroprotection at entry, a “complete response” (both seroresponse and seroprotection) after first vaccination was associated with higher baseline log10 HAI titer and non-Hispanic ethnicity. No serious vaccine-related events occurred.
Conclusion. Two doses of double-strength pH1N1 vaccine are safe and immunogenic and may provide improved protection against influenza in perinatally HIV-1–infected children and youth.
Clinical Trials Registration. NCT00992836.
doi:10.1093/infdis/jis360
PMCID: PMC3490699  PMID: 22615311
4.  Association of Higher Plasma Vitamin D Binding Protein and Lower Free Calcitriol Levels with Tenofovir Disoproxil Fumarate Use and Plasma and Intracellular Tenofovir Pharmacokinetics: Cause of a Functional Vitamin D Deficiency? 
Antimicrobial Agents and Chemotherapy  2013;57(11):5619-5628.
Tenofovir disoproxil fumarate (TDF) causes bone, endocrine, and renal changes by an unknown mechanism(s). Data are limited on tenofovir pharmacokinetics and these effects. Using baseline data from a multicenter study of HIV-infected youth on stable treatment with regimens containing TDF (n = 118) or lacking TDF (n = 85), we measured cross-sectional associations of TDF use with markers of renal function, vitamin D-calcium-parathyroid hormone balance, phosphate metabolism (tubular reabsorption of phosphate and fibroblast growth factor 23 [FGF23]), and bone turnover. Pharmacokinetic-pharmacodynamic associations with plasma tenofovir and intracellular tenofovir diphosphate concentrations were explored among those receiving TDF. The mean age was 20.9 (standard deviation [SD], 2.0) years; 63% were male; and 52% were African American. Compared to the no-TDF group, the TDF group showed lower mean estimated glomerular filtration rates and tubular reabsorption of phosphate, as well as higher parathyroid hormone and 1,25-dihydroxy vitamin D [1,25-OH(2)D] levels. The highest quintile of plasma tenofovir concentrations was associated with higher vitamin D binding protein, lower free 1,25-OH(2)D, higher 25-OH vitamin D, and higher serum calcium. The highest quintile of intracellular tenofovir diphosphate concentration was associated with lower FGF23. Higher plasma tenofovir concentrations were associated with higher vitamin D binding protein and lower free 1,25-OH(2)D, suggesting a functional vitamin D deficiency explaining TDF-associated increased parathyroid hormone. The finding of lower FGF23 accompanying higher intracellular tenofovir diphosphate suggests that different mechanisms mediate TDF-associated changes in phosphate handling. Separate pharmacokinetic properties may be associated with distinct TDF toxicities: tenofovir with parathyroid hormone and altered calcium balance and tenofovir diphosphate with hypophosphatemia and FGF23 regulation.
(The clinical trial registration number for this study is NCT00490412 and is available online at http://clinicaltrials.gov/ct2/show/NCT00490412.)
doi:10.1128/AAC.01096-13
PMCID: PMC3811269  PMID: 24002093
5.  High proportions of regulatory B and T cells are associated with decreased cellular responses to pH1N1 influenza vaccine in HIV-infected children and youth (IMPAACT P1088) 
HIV-infected individuals have poor responses to inactivated influenza vaccines. To evaluate the potential role of regulatory T (Treg) and B cells (Breg), we analyzed their correlation with humoral and cell-mediated immune (CMI) responses to pandemic influenza (pH1N1) monovalent vaccine in HIV-infected children and youth. Seventy-four HIV-infected, 4- to 25-y old participants in a 2-dose pH1N1 vaccine study had circulating and pH1N1-stimulated Treg and Breg measured by flow cytometry at baseline, post-dose 1 and post-dose 2. Concomitantly, CMI was measured by ELISPOT and flow cytometry; and antibodies by hemagglutination inhibition (HAI). At baseline, most of the participants had pH1N1-specific IFNγ ELISPOT responses, whose magnitude positively correlated with the baseline pH1N1, but not with seasonal H1N1 HAI titers. pH1N1-specific IFNγ ELISPOT responses did not change post-dose 1 and significantly decreased post-dose 2. In contrast, circulating CD4+CD25+% and CD4+FOXP3+% Treg increased after vaccination. The decrease in IFNγ ELISPOT results was marginally associated with higher pH1N1-specific CD19+FOXP3+ and CD4+TGFβ+% Breg and Treg, respectively. In contrast, increases in HAI titers post-dose 1 were associated with significantly higher circulating CD19+CD25+% post-dose 1, whereas increases in IFNγ ELISPOT results post-dose 1 were associated with higher circulating CD4+/C8+CD25+FOXP3+%. In conclusion, in HIV-infected children and youth, influenza-specific Treg and Breg may contribute to poor responses to vaccination. However, robust humoral and CMI responses to vaccination may result in increased circulating Treg and/or Breg, establishing a feed-back mechanism.
doi:10.4161/hv.23774
PMCID: PMC3899162  PMID: 23370281
HIV infection; influenza vaccine; cell-mediated immunity; regulatory T cells; regulatory B cells
6.  The Safety of Cefepime and Ceftazidime in Pediatric Oncology Patients 
Pediatric blood & cancer  2013;60(5):806-809.
Background
Concern has been raised about possible increased mortality associated with the use of cefepime. There are limited data available on the pragmatic use of beta-lactam antibiotics, especially in children.
Procedure
This retrospective study included 532 pediatric oncology patients. The outcomes of patients treated with cefepime for suspected serious bacterial infections were compared to those of patients treated with ceftazidime. Primary outcomes included 30- and 90-day all-cause mortality.
Results
The demographic and clinical characteristics of 337 patients treated with ceftazidime were similar to those of 195 patients receiving cefepime. Thirty-day and 90-day all cause mortality rates were comparable (30-day OR for cefepime: 3.48, 95% CI 0.31 to 38.84, P=0.3; 90-day OR: 0.99, 95% CI 0.29 to 3.42, P=1.0]. There were also no differences in infection-related mortality rates, secondary infections, or adverse drug events. Deaths occurring within 30 days of hospitalization were judged to be attributable to infection, but not the result of treatment failure or adverse drug events. Deaths occurring between 30 and 90 days were associated with progressive or new malignancy. Secondary infection was significantly associated with mortality.
Conclusions
The use of cefepime in pediatric oncology patients is not associated with increased mortality when compared to ceftazidime, however the small number of deaths in this study limits the strength of this conclusion. Previous associations between antimicrobial therapy and increased all-cause mortality may have been confounded by patients' demographic characteristics and co-morbid conditions. All-cause mortality may be an insensitive outcome for studies examining the efficacy and safety of these agents.
doi:10.1002/pbc.24467
PMCID: PMC4006133  PMID: 23382054
cefepime; ceftazidime; pediatric; oncology; drug safety
7.  Optimizing Frequency of CD4 Assays in the Era of Highly Active Antiretroviral Therapy 
Abstract
Current HIV guidelines recommend monitoring CD4 counts every 3–4 months. In the era of highly active antiretroviral therapy (HAART) and HIV PCR, this retrospective study reexamines the required frequency of the CD4 assay. Predictor variables, including age, previous CD4 count, HIV viral load (VL), time interval since last VL and CD4 count (TINT), and antiretroviral history, were abstracted. A recursive partitioning-based regression tree analysis was used to determine if the absolute current CD4 count was above or below the age appropriate Pneumocystis jiroveci pneumonia (PCP) prophylaxis cutoff. We analyzed concurrently obtained VLs and CD4 count including 601 results from 43 HIV-infected children aged 1–<6 years (Group I) and 1,364 results from 93 children/adolescents 6–<23 years (Group II). Using 75% of observations to build a predictive model (learning dataset), the ability to correctly predict the range of the outcome variable in the remaining 25% of observations (training dataset) was 93% in Group I and 97% in Group II. Predictor variables included age, recent VL and CD4 count, and TINT. A total of 1,000 repeats of this model building using randomly selected observations showed a correct predictive ability of 89.6% [standard error (SE) 2.3%] in Group I and 95.6% (SE 1%) in Group II. The ability of a classification tree to determine if the current CD4 count is above or below the age-specific cutoff for PCP prophylaxis is very good and allows less frequent CD4 assays. The principles underlying this modeling-based approach have broad applicability and cost saving implications.
doi:10.1089/aid.2012.0175
PMCID: PMC3581070  PMID: 23016543
8.  Genetic associations with 25-hydroxyvitamin D deficiency in HIV-1-infected youth: fine-mapping for the GC/DBP gene that encodes the vitamin D-binding protein 
Frontiers in Genetics  2013;4:234.
Serum 25-hydroxyvitamin D [25(OH)D] is often deficient (<12 ng/ml) or insufficient (<20 ng/ml) in youth living with human immunodeficiency virus type 1 infection (YLH). Based on evidence from multiple genome-wide association studies, we hypothesized that genetic factors associated with 25(OH)D deficiency should be readily detectable in YLH even when controlling for other known factors, including use of the antiretroviral drug efavirenz (EFV). Genotyping by bi-directional sequencing targeted 15 single nucleotide polymorphisms (SNPs) at the GC/DBP locus, with a focus on coding and regulatory variants, as well as those repeatedly reported in the literature. Three intronic SNPs (rs222016, rs222020, and rs222029) in a conserved haplotype block had unequivocal association signals (false discovery rate ≤ 0.006). In particular, the minor allele G for rs222020 was highly unfavorable among 192 YLH (99 African–Americans and 93 others), as gauged by relatively low likelihood for 25(OH)D sufficiency at enrollment (odds ratio = 0.31, p = 9.0 × 10-4). In a reduced multivariable model, race, season, latitude, body mass index, exposure to EFV, and rs222020-G were independent factors that collectively accounted for 38% of variance in the log10-transformed 25(OH)D concentration (p < 0.0001). Interaction terms were evident for rs222020-G × season (p < 0.001), latitude × season (especially fall and winter; p < 0.01), and race × EFV use (p = 0.024). Overall, variance in serum 25(OH)D is substantially attributable to multiple factors, but the exact contribution of genetic and non-genetic factors can be obscured by partial overlaps and frequent interactions.
doi:10.3389/fgene.2013.00234
PMCID: PMC3827582  PMID: 24294218
antiretroviral; genetics; HIV-1; race; youth; vitamin D
9.  Hepatitis B Vaccination in HIV-Infected Youth: A Randomized Trial of Three Regimens 
Background
HIV-infected youth are at risk of hepatitis B (HBV) infection and should be vaccinated. Previous reports suggest reduced response to standard HBV vaccine regimens.
Methods
HIV-infected youth, age 12 to <25 years, were randomly assigned to one of three treatment arms: Arm 1: Engerix B®, 20 mcg HBsAg; Arm 2: Engerix B®, 40 mcg; and Arm 3: Twinrix®, 20mcg HBsAg combined with 720 ELU hepatitis A antigen. Vaccines were administered at weeks 0, 4 and 24.
Results
Characteristics of evaluable patients (n=336) at entry were similar in the study arms. At enrollment, median CD4+ T-cell count was 460 cells/mm3 (IQR: 305 to 668); 13% were < 200 cells/mm3. Among Engerix B®, 20 mcg recipients, 60.4% responded to vaccine (HBsAb ≥ 10 IU/mL at week 28). Improved vaccine response was seen in recipients of Engerix B®, 40 mcg, (73.2%, vs. Arm 1, p=0.04) and Twinrix® (75.4%, vs. Arm 1, p=0.02). In multivariate analysis, only baseline CD4+ T-cell count and study arm were independent predictors of vaccine response.
Conclusions
In HIV-infected youth, a three dose vaccination regimen with Engerix B®, 40 mcg, or Twinrix® and higher baseline CD4+ T-cell counts were independently associated with improved vaccine response.
doi:10.1097/QAI.0b013e318203e9f2
PMCID: PMC3079288  PMID: 21350366
HIV; Hepatitis B Vaccination; Adolescents; Engerix B; Twinrix
10.  Comprehension of a simplified assent form in a vaccine trial for adolescents 
Journal of medical ethics  2013;39(6):410-412.
Introduction
Future HIV vaccine efficacy trials with adolescents will need to ensure that participants comprehend study concepts in order to confer true informed assent. A Hepatitis B vaccine trial with adolescents offers valuable opportunity to test youth understanding of vaccine trial requirements in general.
Methods
Youth reviewed a simplified assent form with study investigators and then completed a comprehension questionnaire. Once enrolled, all youth were tested for HIV and confirmed to be HIV-negative.
Results
123 youth completed the questionnaire (mean age=15 years; 63% male; 70% Hispanic). Overall, only 69 (56%) youth answered all six questions correctly.
Conclusions
Youth enrolled in a Hepatitis B vaccine trial demonstrated variable comprehension of the study design and various methodological concepts, such as treatment group masking.
doi:10.1136/medethics-2012-101286
PMCID: PMC3655100  PMID: 23349510
11.  Vitamin D3 Decreases Parathyroid Hormone in HIV-Infected Youth Being Treated With Tenofovir: A Randomized, Placebo-Controlled Trial 
In this randomized, double-blind, placebo-controlled trial of human immunodeficiency virus–infected youths aged 18–25, vitamin D3, 50000 IU once monthly for 3 months decreased parathyroid hormone in participants treated with tenofovir-containing antiretroviral regimens but not in those participants whose regimens did not contain tenofovir.
Background. The study goal was to determine the effect of vitamin D (VITD) supplementation on tubular reabsorption of phosphate (TRP), parathyroid hormone (PTH), bone alkaline phosphatase (BAP), and C-telopeptide (CTX) in youth infected with human immunodeficiency virus (HIV) receiving and not receiving combination antiretroviral therapy (cART) containing tenofovir disoproxil fumarate (TDF).
Methods. This randomized, double-blind, placebo-controlled multicenter trial enrolled HIV-infected youth 18–25 years based on stable treatment with cART containing TDF (n = 118) or no TDF (noTDF; n = 85), and randomized within those groups to vitamin D3, 50 000 IU (n = 102) or placebo (n = 101), administered at 0, 4, and 8 weeks. Outcomes included change in TRP, PTH, BAP, and CTX from baseline to week 12 by TDF/noTDF; and VITD/placebo.
Results. At baseline, VITD and placebo groups were similar except those on TDF had lower TRP and higher PTH and CTX. At week 12, 95% in the VITD group had sufficient serum 25-hydroxy vitamin D (25-OHD; ≥20 ng/mL), increased from 48% at baseline, without change in placebo (P < .001). PTH decreased in the TDF group receiving VITD (P = .031) but not in the noTDF group receiving VITD, or either placebo group. The decrease in PTH with VITD in those on TDF occurred with insufficient and sufficient baseline 25-OHD (mean PTH change, −7.9 and −6.2 pg/mL; P = .031 and .053, respectively).
Conclusions. In youth on TDF, vitamin D3 supplementation decreased PTH, regardless of baseline 25-OHD concentration.
Clinical Trials Registration. NCT00490412.
doi:10.1093/cid/cir968
PMCID: PMC3297650  PMID: 22267714
12.  Culture, Emotion, and Cancer Screening: an Integrative Framework for Investigating Health Behavior 
Background
Although health disparity research has investigated social structural, cultural, or psychological factors, the interrelations among these factors deserve greater attention.
Purpose
This study aims to examine cancer screening emotions and their relations to screening fatalism as determinants of breast cancer screening among women from diverse socioeconomic and ethnic backgrounds.
Methods
An integrative conceptual framework was used to test the multivariate relations among socioeconomic status, age, screening fatalism, screening emotions, and clinical breast exam compliance among 281 Latino and Anglo women, using multi-group structural equation causal modeling.
Results
Screening emotions and screening fatalism had a negative, direct influence on clinical breast exam compliance for both ethnic groups. Still, ethnicity moderated the indirect effect of screening fatalism on clinical breast exam compliance through screening emotions.
Conclusions
Integrative conceptual frameworks and multivariate methods may shed light on the complex relations among factors influencing health behaviors relevant to disparities. Future research and intervention must recognize this complexity when working with diverse populations.
doi:10.1007/s12160-011-9267-z
PMCID: PMC3584161  PMID: 21472484
Emotions; Culture; Fatalism; Breast cancer screening; Health disparities
14.  Analyses of HIV-1 Drug-Resistance Profiles Among Infected Adolescents Experiencing Delayed Antiretroviral Treatment Switch After Initial Nonsuppressive Highly Active Antiretroviral Therapy 
AIDS Patient Care and STDs  2008;22(7):545-552.
Abstract
Treatment failure and drug resistance create obstacles to long-term management of HIV-1 infection. Nearly 60% of infected persons fail their first highly active antiretroviral therapy (HAART) regimen, partially because of nonadherence, requiring a switch to a second regimen to prevent drug resistance. Among HIV-infected youth, a group with rising infection rates, treatment switch is often delayed; virologic and immunologic consequences of this delay are unknown. We conducted a retrospective, longitudinal study of drug resistance outcomes of initial HAART in U.S. youth enrolled between 1999–2001 in a multicenter, observational study and experiencing delayed switch in their first nonsuppressive treatment regimen for up to 3 years. HIV-1 genotyping was performed on plasma samples collected longitudinally, and changes in drug resistance mutations, CD4+ T cell numbers and viral replication capacity were assessed. Forty-four percent (n = 18) of youth in the parent study experiencing virologic nonsuppression were maintained on their initial HAART regimen for a median of 144 weeks. Drug resistance was detected in 61% (11/18) of subjects during the study. Subjects on non-nucleoside reverse transcriptase inhibitor (NNRTI) regimens developed more (8/10) drug resistance mutations than those on protease-inhibitor (PI) regimens (2/7) (p = 0.058). Subjects developing NNRTI-resistance (NNRTI-R), showed a trend toward lower CD4+ T cell gains (median: −6 cells/mm3 per year) than those without detectable NNRTI-R (median: +149 cells/mm3 per year) (p = 0.16). HIV-1–infected youth maintained on initial nonsuppressive NNRTI-based HAART regimens are more likely to develop drug-resistant viremia than with PI-based HAART. This finding may have implications for initial treatment regimens and transmission risk in HIV-infected youth, a group with rising infection rates.
doi:10.1089/apc.2007.0200
PMCID: PMC2929158  PMID: 18479228
15.  Psychological Factors, Beliefs About Medication, and Adherence of Youth with HIV-1 in a Multisite Directly Observed Therapy (DOT) Pilot Study 
Introduction
Examine psychological functioning and beliefs about medicine in adolescents with HIV-1 on HAART in a community-based directly observed therapy (DOT) pilot feasibility study.
Methods
Youth with behaviorally-acquired HIV (n=20; 65% female; median age 21 years) with adherence problems, received once-daily DOT. Youth were assessed at baseline, week 12 (post-DOT) and week 24 (follow-up).
Results
Baseline to week 12 comparisons: 55% of youth reported clinical depressive symptoms compared to 27% at week 12 with sustained improvements at week 24. Substance use: Borderline clinical range (Tscore=68), with clinical but statistically non-significant improvement (Tscore=61). Hopelessness scores reflected optimism for the future. Coping strategies showed significantly decreased Cognitive Avoidance (p=0.02), Emotional Discharge (p=0.004), and Acceptance/Resignation (“nothing I can do,” p=0.004); Positive Reappraisal and Seeking Support emerged. Aside from depressive symptoms, week 12 improvements were not sustained at week 24. DOT adherence was predicted by higher baseline depression (p=0.05), Beliefs About Medicine (p=0.006) and Perceived Threat of illness scores (p=0.03).
Discussion
Youth with behaviorally-acquired HIV and adherence problems who participated in a community-based DOT intervention reported clinically improved depressive symptoms, and temporarily reduced substance use and negative coping strategies. Depressive symptoms, Beliefs About Medicine and viewing HIV as a threat predicted better DOT adherence.
doi:10.1016/j.jadohealth.2010.09.014
PMCID: PMC3096841  PMID: 21575827
HIV; adolescent; psychological functioning; directly observed therapy (DOT); adherence
16.  Pharmacokinetics and Safety of Single-Dose Tenofovir Disoproxil Fumarate and Emtricitabine in HIV-1-Infected Pregnant Women and Their Infants▿ 
Antimicrobial Agents and Chemotherapy  2011;55(12):5914-5922.
Tenofovir (TFV) is effective in preventing simian immunodeficiency virus (SIV) transmission in a macaque model, is available as the oral agent tenofovir disoproxil fumarate (TDF), and may be useful in the prevention of mother-to-child transmission of human immunodeficiency virus (HIV). We conducted a trial of TDF and TDF-emtricitabine (FTC) in HIV-infected pregnant women and their infants. Women received a single dose of either 600 mg TDF, 900 mg TDF, or 900 mg TDF-600 mg FTC at labor onset or prior to a cesarean section. Infants received no drug or a single dose of TDF at 4 mg/kg of body weight or of TDF at 4 mg/kg plus FTC at 3 mg/kg as soon as possible after birth. All regimens were safe and well tolerated. Maternal areas under the serum concentration-time curve (AUC) and concentrations at the end of sampling after 24 h (C24) were similar between the two doses of TDF; the maximum concentrations of the drugs in serum (Cmax) and cord blood concentrations were higher in women delivering via cesarean section than in those who delivered vaginally (P = 0.04 and 0.046, respectively). The median ratio of the TFV concentration in cord blood to that in the maternal plasma at delivery was 0.73 (range, 0.26 to 1.95). Without TDF administration, infants had a median TFV concentration of 12 ng/ml 12 h after birth. Following administration of a single dose of TDF at 4 mg/kg, infant TFV concentrations fell below the targeted level, 50 ng/ml, by 24 h postdose. In HIV-infected pregnant women and their infants, 600 mg of TDF is acceptable as a single dose during labor. Low concentrations at birth support infant dosing as soon after birth as possible. Rapidly decreasing TFV levels in infants suggest that multiple or higher doses of TDF will be necessary to maintain concentrations that are effective for viral suppression.
doi:10.1128/AAC.00544-11
PMCID: PMC3232794  PMID: 21896911
17.  Randomized Trial to Determine Safety and Immunogenicity of Two Strategies for Hepatitis B Vaccination in Healthy Urban Adolescents in the United States 
Background
Multiple studies have shown excellent response rates after hepatitis B immunization in youth; however, one previous study conducted in urban youth demonstrated poor responses.
Methods
Urban youth, ages 12-17 years, at participating Adolescent Medicine Trials Network for HIV/AIDS Interventions Clinical/Research (ATN) sites were randomized to receive either two doses of Recombivax HB (10mcg hepatitis B surface antigen) or Twinrix (20mcg hepatitis B surface antigen and 720 EL.U hepatitis A antigen) at 0 and 24 weeks. Safety data were collected and antibody measures performed at 0, 28 and 76 weeks.
Results
123 subjects were enrolled and 102 had week 28 serum samples available for antibody measure. A positive response (serum antibody ≥ 10mIU/mL) to hepatitis B antigen was documented in 41/47 (87.2%; 95% confidence interval (CI) 74.3%-95.2%) Recombivax HB recipients and in 52/55 (94.6%; 95% CI 84.9%-98.9%) Twinrix recipients (p=.295). In an adjusted analysis, those identified as Hispanic ethnicity (N=86) were more likely to have a positive response (odds ratio 7.38, 95% confidence interval 1.56-34.95; p=0.0018); whereas those who identified as not heterosexual (N=9) were less likely to respond (odds ratio=0.12, 95%CI, 0.02-0.74). The majority of youth in the Twinrix arm were hepatitis A antibody positive at baseline (26/51; 51%); however, 24/25 hepatitis A antibody negative youth responded to the hepatitis A component. Both vaccines were safe.
Conclusions
Response rate to two doses of Recombivax HB in urban youth is lower than previous studies suggest. The factors associated with diminished response are not known.
doi:10.1097/INF.0b013e3181d285c7
PMCID: PMC3274492  PMID: 20173677
Adolescents; hepatitis B; Vaccination; Immunogenicity
18.  Healthcare Mistreatment and Continuity of Cancer Screening among Latino and Anglo American Women in Southern California 
Women & health  2011;51(1):1-24.
The aim of this research was to examine the relation of perceptions of healthcare mistreatment and related emotions to continuity of cancer screening care among women who reported healthcare mistreatment. The structure of relations among cultural beliefs about healthcare professionals, perceptions of mistreatment, mistreatment-related emotions, and continuity of screening was investigated. Participants included 313 Anglo and Latino American women of varying demographic characteristics from Southern California who were recruited using multistage stratified sampling. Structural equation modeling confirmed the relation of perceptions of mistreatment to continuity of care for both Anglo and Latino American women, with ethnicity moderating this association. For Anglo Americans, greater perceptions of mistreatment were negatively related to continuity of screening. However, for Latinas the relation was indirect, through mistreatment-related anger. While greater perceptions of mistreatment were associated with higher levels of anger for both ethnic groups, anger was negatively related to continuity of care for Latino but not for Anglo women. Furthermore, cultural beliefs about professionals were indirectly related to continuity of screening through perceptions of mistreatment and/or mistreatment-related anger. These findings highlight the importance of the role of cultural and psychological factors in research and interventions aimed at improving patient-professional relations with culturally diverse women.
doi:10.1080/03630242.2011.541853
PMCID: PMC3086030  PMID: 21391158
perceived mistreatment; emotions; culture; cancer screening; health disparities
19.  A cultural research approach to instrument development: the case of breast and cervical cancer screening among Latino and Anglo women 
Health Education Research  2010;25(6):991-1007.
To illustrate the implementation of a bottom-up approach to the study of culture in health disparities, this article describes the development of a cultural cancer screening scale (CCSS) using mixed methodologies. The aim was to identify cultural factors relevant to breast and cervical cancer screening, develop an instrument to assess them and examine its preliminary psychometric properties among Latin American (Latino) and non-Latino White (Anglo) women in Southern California. Seventy-eight Latino and Anglo women participated in semi-structured interviews, which were content coded based on Triandis' methods for the analysis of subjective culture. Based on the emerging cultural elements, items relevant to cancer screening were developed and pilot tested with 161 participants. After the instrument was refined, 314 Latino and Anglo women from various socioeconomic backgrounds completed the CCSS and data were factor analyzed resulting in five cultural factors: cancer screening fatalism, negative beliefs about health professionals, catastrophic disease expectations, symptomatic deterrents and sociocultural deterrents. The instrument demonstrated measurement equivalence, adequate reliability and predictive validity. The research and the CCSS are discussed in terms of implications for the study of culture in relation to health disparities and the development of evidence-based interventions with culturally diverse populations and their health professionals.
doi:10.1093/her/cyq052
PMCID: PMC2974838  PMID: 20864605
20.  Directly Observed Therapy (DOT) for Nonadherent HIV-Infected Youth: Lessons Learned, Challenges Ahead 
Abstract
Adherence to medications is critical to optimizing HIV care and is a major challenge in youth. The utility of directly observed therapy (DOT) to improve adherence in youth with HIV remains undefined and prompted this pilot study. Four U.S. sites were selected for this 24-week cooperative group study to assess feasibility and to identify the logistics of providing DOT to HIV-infected youth with demonstrated adherence problems. Once-a-day DOT was provided by DOT facilitators at the participant's choice of a community-based location and DOT tapered over 12 weeks to self-administered therapy based on ongoing adherence assessments. Twenty participants, median age 21 years and median CD4 227 cells/μl, were enrolled. Participants chose their homes for 82% of DOT visits. Compliance with recommended DOT visits was (median) 91%, 91%, and 83% at weeks 4, 8, and 12, respectively. Six participants completed >90% of the study-specified DOT visits and successfully progressed to self-administered therapy (DOT success); only half sustained >90% medication adherence 12 weeks after discontinuing DOT. Participants considered DOT successes were more likely to have higher baseline depression scores (p = 0.046). Via exit surveys participants reported that meeting with the facilitator was easy, DOT increased their motivation to take medications, they felt sad when DOT ended, and 100% would recommend DOT to a friend. In conclusion, this study shows that while community-based DOT is safe, feasible, and as per participant feedback, acceptable to youth, DOT is not for all and the benefits appear short-lived. Depressed youth appear to be one subgroup that would benefit from this intervention. Study findings should help inform the design of larger community-based DOT intervention studies in youth.
doi:10.1089/aid.2010.0008
PMCID: PMC2957634  PMID: 20707731
21.  Vaccinees against the 1976 “swine flu” have enhanced neutralization responses to the 2009 novel H1N1 influenza virus 
Background
The world is facing a novel H1N1 pandemic. A pandemic scare with a similar virus in 1976 resulted in the vaccination of nearly 45 million persons. We hypothesized that prior receipt of the 1976 “swine flu” vaccine would enhance immune responses to the 2009 novel H1N1 strain.
Methods
A prospective, volunteer sample of employees 55 years of age and older at a children’s cancer hospital in August of 2009 was assessed for antibody responses to the 2009 pandemic H1N1 influenza virus and the 2008-2009 seasonal H1N1 influenza virus.
Results
Antibody responses by hemagglutination-inhibition assay were high against both the seasonal (89.7% had a titer considered seroprotective) and pandemic (88.8% had a seroprotective titer) H1N1 viruses. These antibodies were effective at neutralizing the seasonal H1N1 virus in 68.1% of participants (titer ≥ 40), but only 18.1% had detectable neutralizing titers against the pandemic H1N1. Of 116 participants, 46 (39.7%) received the 1976 “swine flu” vaccine. Receipt of this vaccine significantly enhanced neutralization responses as 8 of 46 (17.4%) vaccine recipients had titers ≥ 160 compared to only 3 of 70 (4.3%) who did not receive the vaccine (P = 0.018 by chi-squared test).
Conclusions
In this cohort, persons 55 years and older had evidence of robust immunity to the 2008-2009 seasonal H1N1 virus. These antibodies were cross-reactive but non-neutralizing against the 2009 pandemic H1N1 strain. Receipt of a vaccine to a related virus significantly enhanced the neutralization capacity of these responses, suggesting homologous vaccination against the 2009 pandemic H1N1 would have a similar effect.
doi:10.1086/652441
PMCID: PMC2946351  PMID: 20415539
22.  Panton–Valentine Leukocidin-Positive Methicillin-Resistant Staphylococcus aureus Infections in Children With Cancer 
Pediatric blood & cancer  2009;53(7):1216-1220.
Background
New strains of methicillin-resistant Staphylococcus aureus (MRSA) which frequently carry the Panton–Valentine leukocidin (PVL) genes have been recognized to cause invasive infections in otherwise healthy children and adults. However, the epidemiology of PVL-positive MRSA infections has not been described in children or adults with cancer.
Procedure
The epidemiology of MRSA infections in patients with cancer was retrospectively studied from 2000 to 2007. Molecular typing was performed by polymerase chain reaction (PCR) for the detection of the PVL genes. Staphylococcus cassette chromosome (SCC) mec and spa typing was performed on all PVL-positive isolates.
Results
A total of 88 MRSA isolates from clinically distinct infectious episodes were collected from 88 patients with cancer during the 8-year study period. Infections were predominant in the skin and soft tissues (SSTI; P =0.0003). PVL-positive isolates, bearing the type IV SCCmec element, encoding the gene for methicillin resistance, increased significantly during this period (P =0.043) and comprised 35 of 88 (40%) MRSA isolates. Of these 35 isolates, 32 belonged to spa type 8 and were USA300 genotype. Patients infected with PVL-positive strains did not have more SSTI (P =0.166) or bacteremia (P =0.510) as compared to patients with PVL-negative strains. A greater percentage of PVL-positive isolates were susceptible to ciprofloxacin (P =0.006).
Conclusions
PVL-positive MRSA infections are not associated with a higher morbidity as compared to PVL-negative MRSA infections in children with cancer.
doi:10.1002/pbc.22254
PMCID: PMC3075015  PMID: 19731325
cancer; children; methicillin-resistant Staphylococcus aureus; Panton-Valentine leukocidin
23.  Short Communication: Methicillin-Resistant Staphylococcus aureus Infections in Children and Young Adults Infected with HIV 
AIDS Research and Human Retroviruses  2009;25(12):1219-1224.
Abstract
The epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) infections, in particular with Panton-Valentine leukocidin (PVL)-positive strains, has not been well characterized in children and young adults with HIV infection. It is not known if PVL-positive strains of MRSA cause an increased morbidity in this population compared to PVL-negative strains. The purpose of this study was to retrospectively analyze the epidemiology of PVL-positive and PVL-negative MRSA infections in children and young adults with HIV from 2000 to 2007. Molecular typing was performed by polymerase chain reaction (PCR) for detection of the PVL genes. Staphylococcus Cassette Chromosome (SCC) mec and spa typing were performed on all PVL-positive isolates. The number of HIV patients with MRSA infection increased significantly between 2000 and 2007 (p = 0.0015). Twenty seven (87%) of the 31 MRSA isolates were from skin and soft tissue infections (SSTI). Clindamycin resistance was observed in 19% of the MRSA isolates. PVL-positive isolates bearing the type IV SCC mec element comprised 16 of 31 (52%) MRSA isolates. All the PVL-positive isolates belonged to the USA300 pulsed-field type. There was no difference in the mean CD4 count and HIV viral load between patients with PVL-positive and PVL-negative MRSA infections. PVL-positive MRSA infections were associated with more SSTI (p = 0.043) but not with increased morbidity or a higher risk of complications compared to PVL-negative MRSA infections in children and young adults with HIV.
doi:10.1089/aid.2009.0040
PMCID: PMC2858900  PMID: 20001313
24.  Etiology and Clinical Course of Febrile Neutropenia in Children with Cancer 
Background
The etiology, clinical course and outcome of fever and neutropenia (FN) in children with cancer using the current FN guidelines and diagnostic resources in the United States have not been well described.
Patients and Methods
Medical records of one randomly selected FN episode per patient during 2004–2005 at a pediatric oncology center were reviewed. Patients were managed as per institutional FN guidelines and blood cultures collected in continuously-read BACTEC™ bottles.
Results
Of 337 FN episodes, infection was proven in 86 (25%) and probable in 75 (22%). 177 episodes (53%) were judged fever of unknown origin (FUO). Bacteremia accounted for most (41) of the proven bacterial episodes, with viridans streptococci (13), Pseudomonas spp (6) and E. coli (6) the most frequently isolated organisms. The median time to positivity of blood cultures was 12 hrs (range 5.4 – 143.7) with 93% positive within 24 hours of incubation. Viral pathogens were identified in 29 (34%) episodes. Compared to other patients, those with FUO had shorter median duration of fever (0.5 vs. 2.0 days; p<0.0001) and hospitalization (3 vs. 6 days; p<0.0001), longer median duration since last chemotherapy (6.0 vs. 4.0 days; p=0.01) and were less likely to have a diagnosis of acute myelogenous leukemia (AML) (11% vs 22%; p=0.009) or develop a clinical complication (5.1% vs 24.4%; p<0.0001).
Conclusion
Despite currently available diagnostic resources, the majority of patients with FN have FUO marked by a low rate of clinical complications and no infection-related mortality. Emergence of viridans streptococci as the most common blood isolate has affected FN treatment recommendations. Study findings will help further development of strategies for risk stratified management of fever with neutropenia in pediatric patients.
doi:10.1097/MPH.0b013e3181b1edc6
PMCID: PMC2743072  PMID: 19644403
Fever; Neutropenia; Children; Microbiology; Etiology
25.  Development of a Directly Observed Therapy (DOT) Adherence Intervention for Adolescents with HIV-1: Application of Focus Group Methodology to Inform Design, Feasibility and Acceptability 
Purpose
To obtain input from adolescents with HIV-1 infection to inform the design of a community-based modified directly observed therapy (MDOT) antiretroviral adherence intervention.
Methods
Pediatric AIDS Clinical Trials Group (PACTG) protocol 1036A conducted three focus groups with 17 adolescents aged 17 to 22 years (10 females, 65% African-American) from three geographically distinct US PACTG sites. Focus group sessions were scripted, audio-taped, and transcribed verbatim. A coding dictionary was developed and validated; Ethnograph v5.08 was used to summarize coded data across and within the three sites. Prevalent themes were identified via frequencies and are reported as percents.
Results
Adolescents specified: the MDOT provider should be familiar to the participant and empathic; the MDOT location should be mutually agreed upon, flexible, and private; and participant and provider communication should be bidirectional, preferably by phone. Ideally the MDOT program should be continued until adolescents independently demonstrate adherence and include a weaning phase as a test of skill-acquisition. The most commonly endorsed barrier to the proposed program was MDOT would be an invasion of privacy. Initially, following introduction to the purpose of the focus group, all but one adolescent expressed MDOT could benefit someone other than themselves; however, at conclusion of the focus group discussion, a significant shift in openness to the intervention occurred whereby 11 participants indicated they would consider participation in a MDOT program if offered.
Conclusions
Focus group feedback clarified the feasibility, logistics, and patient concerns about the design and implementation of a proposed MDOT intervention for adolescents with HIV-1 infection who struggle with medication adherence
doi:10.1016/j.jadohealth.2008.05.006
PMCID: PMC2659610  PMID: 19167660
Adolescents; HIV; modified directly observed therapy (MDOT); focus group; adherence

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