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1.  Effectiveness of 7-Valent Pneumococcal Conjugate Vaccine Against Invasive Pneumococcal Disease in HIV-Infected and -Uninfected Children in South Africa: A Matched Case-Control Study 
Cohen, Cheryl | von Mollendorf, Claire | de Gouveia, Linda | Naidoo, Nireshni | Meiring, Susan | Quan, Vanessa | Nokeri, Vusi | Fortuin-de Smit, Melony | Malope-Kgokong, Babatyi | Moore, David | Reubenson, Gary | Moshe, Mamokgethi | Madhi, Shabir A. | Eley, Brian | Hallbauer, Ute | Kularatne, Ranmini | Conklin, Laura | O'Brien, Katherine L. | Zell, Elizabeth R. | Klugman, Keith | Whitney, Cynthia G. | von Gottberg, Anne | Moore, David | Verwey, Charl | Varughese, Sheeba | Archary, Moherndran | Naby, Fathima | Dawood, Khathija | Naidoo, Ramola | Elliott, Gene | Hallbauer, Ute | Eley, Brian | Nuttall, James | Cooke, Louise | Finlayson, Heather | Rabie, Helena | Whitelaw, Andrew | Perez, Dania | Jooste, Pieter | Naidoo, Dhamiran | Kularatne, Ranmini | Reubenson, Gary | Cohen, Cheryl | de Gouveia, Linda | du Plessis, Mignon | Govender, Nevashan | Meiring, Susan | Quan, Vanessa | von Mollendorf, Claire | Fortuin-de Smidt, Melony | Naidoo, Nireshni | Malope-Kgokong, Babatyi | Nokeri, Vusi | Ncha, Relebohile | Lindani, Sonwabo | von Gottberg, Anne | Spies, Barry | Sono, Lino | Maredi, Phasweni | Hamese, Ken | Moshe, Mamokgethi | Nchabeleng, Maphosane | Ngcobo, Ntombenhle | van den Heever, Johann | Madhi, Shabir | Conklin, Laura | Verani, Jennifer | Whitney, Cynthia | Zell, Elizabeth | Loo, Jennifer | Nelson, George | Klugman, Keith | O'Brien, Katherine
A 2 + 1 seven-valent pneumococcal conjugate vaccine schedule is effective against vaccine-serotype invasive pneumococcal disease (IPD) in HIV-uninfected children and HIV-exposed but -uninfected children and against all-serotype multidrug-resistant IPD in HIV-uninfected children.
Background. South Africa introduced 7-valent pneumococcal conjugate vaccine (PCV7) in April 2009 using a 2 + 1 schedule (6 and 14 weeks and 9 months). We estimated the effectiveness of ≥2 PCV7 doses against invasive pneumococcal disease (IPD) in human immunodeficiency virus (HIV)–infected and -uninfected children.
Methods. IPD (pneumococcus identified from a normally sterile site) cases were identified through national laboratory-based surveillance. Specimens were serotyped by Quellung or polymerase chain reaction. Four controls, matched for age, HIV status, and hospital were sought for each case. Using conditional logistic regression, we calculated vaccine effectiveness (VE) as 1 minus the adjusted odds ratio for vaccination.
Results. From March 2010 through November 2012, we enrolled 187 HIV-uninfected (48 [26%] vaccine serotype) and 109 HIV-infected (43 [39%] vaccine serotype) cases and 752 HIV-uninfected and 347 HIV-infected controls aged ≥16 weeks. Effectiveness of ≥2 PCV7 doses against vaccine-serotype IPD was 74% (95% confidence interval [CI], 25%–91%) among HIV-uninfected and −12% (95% CI, −449% to 77%) among HIV-infected children. Effectiveness of ≥3 doses against vaccine-serotype IPD was 90% (95% CI, 14%–99%) among HIV-uninfected and 57% (95% CI, −371% to 96%) among HIV-infected children. Among HIV-exposed but -uninfected children, effectiveness of ≥2 doses was 92% (95% CI, 47%–99%) against vaccine-serotype IPD. Effectiveness of ≥2 doses against all-serotype multidrug-resistant IPD was 96% (95% CI, 62%–100%) among HIV-uninfected children.
Conclusions. A 2 + 1 PCV7 schedule was effective in preventing vaccine-serotype IPD in HIV-uninfected and HIV-exposed, uninfected children. This finding supports the World Health Organization recommendation for this schedule as an alternative to a 3-dose primary series among HIV-uninfected individuals.
PMCID: PMC4144265  PMID: 24917657
children; HIV; pneumococcus; pneumococcal conjugate vaccine; South Africa
2.  Acute dietary nitrate supplementation does not augment submaximal forearm exercise hyperemia in healthy young men 
Despite the popularity of dietary nitrate supplementation and the growing evidence base of its potential ergogenic and vascular health benefits, there is no direct information about its effects on exercising limb blood flow in humans. We hypothesized that acute dietary nitrate supplementation from beetroot juice would augment the increases in forearm blood flow, as well as the progressive dilation of the brachial artery, during graded handgrip exercise in healthy young men. In a randomized, double-blind, placebo-controlled crossover study, 12 young (22 ± 2 years) healthy men consumed a beetroot juice (140 mL Beet-It Sport, James White Juice Company) that provided 12.9 mmol (0.8 g) of nitrate or placebo (nitrate-depleted Beet-It Sport) on 2 study visits. At 3 h postconsumption, brachial artery diameter, flow, and blood velocity were measured (Doppler ultrasound) at rest and during 6 exercise intensities. Nitrate supplementation raised plasma nitrate (19.5-fold) and nitrite (1.6-fold) concentrations, and lowered resting arterial pulse wave velocity (PWV) versus placebo (all p < 0.05) indicating absorption, conversion, and a biological effect of this supplement. The supplement-associated lowering of PWV was also negatively correlated with plasma nitrite (r = -0.72, p = 0.0127). Despite these systemic effects, nitrate supplementation had no effect on brachial artery diameter, flow, or shear rates at rest (all p ≥ 0.28) or during any exercise workload (all p ≥ 0.18). These findings suggest that acute dietary nitrate supplementation favorably modifies arterial PWV, but does not augment blood flow or brachial artery vasodilation during non-fatiguing forearm exercise in healthy young men.
PMCID: PMC4314377  PMID: 25536008
inorganic nitrate; vascular function; pulse wave velocity
3.  Predictors of unstructured antiretroviral treatment interruption and resumption among HIV-positive individuals in Canada 
HIV medicine  2014;16(2):76-87.
Sustained optimal use of combination antiretroviral treatment (cART) has been shown to decrease morbidity, mortality and HIV transmission. However, incomplete adherence and treatment interruption (TI) remain challenges to the full realization of the promise of cART. We estimated trends and predictors of treatment interruption and resumption among individuals in the Canadian Observational Cohort (CANOC) collaboration.
cART-naïve individuals ≥18 years of age who initiated cART between 2000–2011 were included. We defined TIs as ≥90 consecutive days off cART. We used descriptive analyses to study TI trends over time and Cox regression to identify factors predicting time to first TI and time to treatment resumption after a first TI.
7,633 participants were eligible, of whom 1,860 (24.5%) experienced a TI. The prevalence of TI in the first calendar year of cART decreased by half over the study period. Our analyses highlighted a higher risk of TI among women (adjusted hazard ratio (aHR): 1.59, 95%CI: 1.33–1.92), younger individuals (aHR: 1.27, 95%CI: 1.15–1.37 per decade increase), earlier treatment initiators (CD4 count ≥350 versus <200 mm3, aHR: 1.46, 95%CI: 1.17–1.81), Aboriginal participants (aHR: 1.67, 95%CI: 1.27–2.20), injecting drug users (aHR: 1.43, 95%CI: 1.09–1.89), and users of zidovudine versus tenofovir in the initial cART regimen (aHR: 2.47, 95%CI: 1.92–3.20). Conversely, factors predicting treatment resumption were male sex, older age, and a CD4 cell count <200 mm3 at cART initiation.
Despite significant improvements in cART since its advent, our results demonstrate that TIs remain relatively prevalent. Strategies to support continuous HIV treatment are needed to maximize the benefits of cART.
PMCID: PMC4300259  PMID: 25174373
Treatment interruption; HIV; antiretroviral therapy; retention; Canada
4.  Association of Dietary Factors with Presence and Severity of Tinnitus in a Middle-Aged UK Population 
PLoS ONE  2014;9(12):e114711.
The impact of dietary factors on tinnitus has received limited research attention, despite being a considerable concern among people with tinnitus and clinicians. The objective was to examine the link between dietary factors and presence and severity of tinnitus.
This study used the UK Biobank resource, a large cross-sectional study of adults aged 40–69. 171,722 eligible participants were asked questions specific to tinnitus (defined as noises such as ringing or buzzing in the head or ears). Dietary factors included portions of fruit and vegetables per day, weekly fish consumption (oily and non-oily), bread type, cups of caffeinated coffee per day, and avoidance of dairy, eggs, wheat and sugar. We controlled for lifestyle, noise exposure, hearing, personality and comorbidity factors.
Persistent tinnitus, defined as present at least a lot of the time, was elevated with increased: (i) fruit/vegetable intake (OR = 1.01 per portion/day), (ii) bread (wholemeal/wholegrain, OR = 1.07; other bread, 1.20) and (iii) dairy avoidance (OR = 1.27). Persistent tinnitus was reduced with: (i) fish consumption (non-oily, OR = 0.91; oily, 0.95), (ii) egg avoidance (OR = 0.87) and (iii) caffeinated coffee consumption (OR = 0.99 per cup/day). Reports of “bothersome” tinnitus (moderate-severe handicap) increased with wholemeal/wholegrain bread intake (OR = 0.86). Reports of less frequent transient tinnitus increased with dairy avoidance (OR = 1.18) and decreased with caffeinated coffee (OR = 0.98 per cup/day) and brown bread (OR = 0.94).
This is the first population study to report the association between dietary factors and tinnitus. Although individually dietary associations are mostly modest, particular changes in diet, such as switching between foodstuffs, may result in stronger associations. These findings offer insights into possible dietary associations with tinnitus, and this may be useful when discussing management options in combination with other lifestyle changes and therapies.
PMCID: PMC4264778  PMID: 25503070
5.  Methodological issues and recommendations for systematic reviews of prognostic studies: an example from cardiovascular disease 
Systematic Reviews  2014;3(1):140.
Prognostic factors are associated with the risk of future health outcomes in individuals with a particular health condition. The prognostic ability of such factors is increasingly being assessed in both primary research and systematic reviews. Systematic review methodology in this area is continuing to evolve, reflected in variable approaches to key methodological aspects. The aim of this article was to (i) explore and compare the methodology of systematic reviews of prognostic factors undertaken for the same clinical question, (ii) to discuss implications for review findings, and (iii) to present recommendations on what might be considered to be ‘good practice’ approaches.
The sample was comprised of eight systematic reviews addressing the same clinical question, namely whether ‘aspirin resistance’ (a potential prognostic factor) has prognostic utility relative to future vascular events in patients on aspirin therapy for secondary prevention. A detailed comparison of methods around study identification, study selection, quality assessment, approaches to analysis, and reporting of findings was undertaken and the implications discussed. These were summarised into key considerations that may be transferable to future systematic reviews of prognostic factors.
Across systematic reviews addressing the same clinical question, there were considerable differences in the numbers of studies identified and overlap between included studies, which could only partially be explained by different study eligibility criteria. Incomplete reporting and differences in terminology within primary studies hampered study identification and selection process across reviews. Quality assessment was highly variable and only one systematic review considered a checklist for studies of prognostic questions. There was inconsistency between reviews in approaches towards analysis, synthesis, addressing heterogeneity and reporting of results.
Different methodological approaches may ultimately affect the findings and interpretation of systematic reviews of prognostic research, with implications for clinical decision-making.
Electronic supplementary material
The online version of this article (doi:10.1186/2046-4053-3-140) contains supplementary material, which is available to authorized users.
PMCID: PMC4265412  PMID: 25466903
Systematic review methodology; Prognostic utility; Prognostic factor; Aspirin resistance; Cardiovascular disease; Search strategy; Study selection; Quality assessment; Reporting bias
6.  Modulation of BK Channel by MicroRNA-9 in Neurons After Exposure to HIV and Methamphetamine 
MicroRNAs (miR) regulate phenotype and function of neurons by binding to miR-response elements (MRE) in the 3′ untranslated regions (3′UTR) of various messenger RNAs to inhibit translation. MiR expression can be induced or inhibited by environmental factors like drug exposure and viral infection, leading to changes in cellular physiology. We hypothesized that the effects of methamphetamine (MA) and human immunodeficiency virus (HIV)-infection in the brain will induce changes in miR expression, and have downstream regulatory consequences in neurons. We first used a PCR-based array to screen for differential expression of 380 miRs in frontal cortex autopsy tissues of HIV-positive MA abusers and matched controls. These results showed significantly increased expression of the neuron-specific miR-9. In vitro, we used SH-SY5Y cells, an experimental system for dopaminergic studies, to determine miR expression by quantitative PCR after exposure to MA in the presence or absence of conditioned media from HIV-infected macrophages. Again, we found that miR-9 was significantly increased compared to controls. We also examined the inwardly rectifying potassium channel, KCNMA1, which has alternative splice variants that contain an MRE to miR-9. We identified alternate 3′UTRs of KCNMA1 both in vitro and in the autopsy specimens and found differential splice variant expression of KCNMA1, operating via the increased miR-9. Our results suggest that HIV and MA -induced elevated miR-9, leading to suppression of MRE-containing splice variants of KCNMA1, which may affect neurotransmitter release in dopaminergic neurons.
PMCID: PMC3715589  PMID: 23508624
BK-channel; microRNA; microRNA-9; methamphetamine; human immunodeficiency virus; HIV; neuron; brain
7.  Real-World Impact of Neurocognitive Deficits in Acute and Early HIV Infection 
Journal of neurovirology  2013;19(6):10.1007/s13365-013-0218-2.
The acute and early period of HIV-1 infection (AEH) is characterized by neuroinflammatory and immunopathogenic processes that can alter the integrity of neural systems and neurocognitive functions. However, the extent to which central nervous system changes in AEH confer increased risk of real-world functioning (RWF) problems is not known. In the present study, 34 individuals with AEH and 39 seronegative comparison participants completed standardized neuromedical, psychiatric, and neurocognitive research evaluations, alongside a comprehensive assessment of RWF that included cognitive symptoms in daily life, basic and instrumental activities of daily living, clinician-rated global functioning, and employment. Results showed that AEH was associated with a significantly increased risk of dependence in RWF, which was particularly elevated among AEH persons with global neurocognitive impairment (NCI). Among those with AEH, NCI (i.e., deficits in learning and information processing speed), mood disorders (i.e., Bipolar Disorder), and substance dependence (e.g., methamphetamine dependence) were all independently predictive of RWF dependence. Findings suggest that neurocognitively impaired individuals with AEH are at notably elevated risk of clinically significant challenges in normal daily functioning. Screening for neurocognitive, mood, and substance use disorders in AEH may facilitate identification of individuals at high risk of functional dependence who may benefit from psychological and medical strategies to manage their neuropsychiatric conditions.
PMCID: PMC3865175  PMID: 24277439
Infectious disease; Disability; Substance use; Neuropsychology; AIDS-related Dementia
8.  Effects of Dosage, Comorbidities, and Food on Isoniazid Pharmacokinetics in Peruvian Tuberculosis Patients 
Antimicrobial Agents and Chemotherapy  2014;58(12):7164-7170.
Poor response to tuberculosis (TB) therapy might be attributable to subtherapeutic levels in drug-compliant patients. Pharmacokinetic (PK) parameters can be affected by several factors, such as comorbidities or the interaction of TB drugs with food. This study aimed to determine the PK of isoniazid (INH) in a Peruvian TB population under observed daily and twice-weekly (i.e., biweekly) therapy. Isoniazid levels were analyzed at 2 and 6 h after drug intake using liquid chromatography mass spectrometric methods. A total of 107 recruited patients had available PK data; of these 107 patients, 42.1% received biweekly isoniazid. The mean biweekly dose (12.8 mg/kg of body weight/day) was significantly lower than the nominal dose of 15 mg/kg/day (P < 0.001), and this effect was particularly marked in patients with concurrent diabetes and in males. The median maximum plasma concentration (Cmax) and area under the concentration-time curve from 0 to 6 h (AUC0–6) were 2.77 mg/liter and 9.71 mg·h/liter, respectively, for daily administration and 8.74 mg/liter and 37.8 mg·h/liter, respectively, for biweekly administration. There were no differences in the Cmax with respect to gender, diabetes mellitus (DM) status, or HIV status. Food was weakly associated with lower levels of isoniazid during the continuation phase. Overall, 34% of patients during the intensive phase and 33.3% during the continuation phase did not reach the Cmax reference value. However, low levels of INH were not associated with poorer clinical outcomes. In our population, INH exposure was affected by weight-adjusted dose and by food, but comorbidities did not indicate any effect on PK. We were unable to demonstrate a clear relationship between the Cmax and treatment outcome in this data set. Twice-weekly weight-adjusted dosing of INH appears to be quite robust with respect to important potentially influential patient factors under program conditions.
PMCID: PMC4249529  PMID: 25224007
9.  Branched Oligopeptides Form Nano-Capsules with Lipid Vesicle Characteristics 
In a recent article (Gudlur et al., (2012) PLOS ONE, 7 (9) e45374) we described the special properties of a mixed branched peptide assembly in which equimolar bis(FLIVI)-K-KKKK and bis(FLIVIGSII)-K-KKKK self-associate to form bilayer delimited capsules capable of trapping solutes. These poly-cationic vesicle-like capsules are readily taken up by epithelial cells in culture, escape or evade the endocytic pathway, and accumulate in the peri-nuclear region where they persist without any apparent degradation. In this report we examine the lipid-like properties of this system including initial assembly; solute encapsulation and washing; fusion and resizing by membrane extrusion through polycarbonate filters with defined pore sizes. The resized peptide capsules have uniform diameters in nm size ranges. Once resized, the capsules can be maintained at the new size by storing them at 4° C. Having the ability to prepare stable uniform nano-scale capsules of desired sizes makes them potentially attractive as biocompatible delivery vehicles for various solutes/drugs.
PMCID: PMC3889211  PMID: 24188529
nano capsules; peptide capsules; branched amphiphilic peptides; self-assembling peptides; peptide vesicles
10.  Dried Blood Spots for qPCR Diagnosis of Acute Bartonella bacilliformis Infection 
Bartonella bacilliformis is the etiological agent of a life-threatening illness. Thin blood smear is the most common diagnostic method for acute infection in endemic areas of Peru but remains of limited value because of low sensitivity. The aim of this study was to adapt a B. bacilliformis-specific real-time polymerase chain reaction (PCR) assay for use with dried blood spots (DBS) as a sampling method and assess its performance and use for the diagnosis and surveillance of acute Bartonella infection. Only two of 65 children (3%) that participated in this study had positive blood smears for B. bacilliformis, whereas 16 (including these two) were positive by PCR performed on DBS samples (24.6%). The use of DBS in combination with B. bacilliformis-specific PCR could be a useful tool for public health in identifying and monitoring outbreaks of infection and designing control programs to reduce the burden of this life-threatening illness.
PMCID: PMC3820349  PMID: 24043691
11.  Dynamic Indices of Methamphetamine Dependence and HIV Infection Predict Fluctuations in Affective Distress: A Five-year Longitudinal Analysis 
Journal of affective disorders  2013;151(2):10.1016/j.jad.2013.07.036.
Methamphetamine (METH) use and human immunodeficiency virus (HIV) infection are highly comorbid, and both are associated with increased prevalence of affective distress. Delineating the trajectory of affective distress in the context of METH dependence and HIV infection is important given the implications for everyday functional impairment, adverse health behaviors, and increased risk for adverse health outcomes.
We conducted a five-year longitudinal investigation involving 133 METH-dependent (74 HIV seropositive) and 163 non-METH-dependent (90 HIV seropositive) persons to examine both long-standing patterns and transient changes in affective distress. Mixed-effect regression models with random subject-specific slopes and intercepts evaluated the effect of METH dependence, HIV serostatus, and related variables on affective distress, as measured by the Profile of Mood States.
Transient changes in affective distress were found to be greater among those with a diagnosis of current MDD, briefer durations of abstinence from METH, and higher quantity of METH consumed. Weak associations were observed among static (time-independent predictors) covariates and long-standing patterns in affective distress.
Study lacked data pertaining to the participants’ involvement in METH treatment and relied on respondent-driven sampling.
Our longitudinal investigation of the trajectory of affective distress indicated that specific and dynamic indices of current METH use were associated with greater transient changes in mood. In the evaluation and treatment of affective distress, recency and quantity of current METH use are important to consider given their association with heightened affective distress and mood instability over time.
PMCID: PMC3845675  PMID: 24012068
Affective distress; Methamphetamine; Dependence; HIV; Longitudinal
12.  Sex hormone pathway gene polymorphisms are associated with risk of advanced hepatitis C-related liver disease in males 
Background: Males have excess advanced liver disease and cirrhosis risk including from chronic hepatitis C virus (HCV) infection though the reasons are unclear. Goal: To examine the role variants in genes involved in androgen and estrogen biosynthesis and metabolism play in HCV-related liver disease risk in males. Methods: We performed a cross-sectional study evaluating single nucleotide polymorphisms (SNPs) in 16 candidate genes involved in androgen and estrogen ligand and receptor synthesis and risk of advanced hepatic fibrosis (F3/F4-F4) and inflammation (A2/A3-A3). We calculated adjusted odds ratios (ORs) using logistic regression and used multifactor dimensionality reduction (MDR) analysis to assess for gene-environment interaction. Results: Among 466 chronically HCV-infected males, 59% (n = 274) had advanced fibrosis and 54% (n = 252) had advanced inflammation. Nine of 472 SNPs were significantly associated with fibrosis risk; 4 in AKR1C3 (e.g., AKR1C3 rs2186174: ORadj = 2.04, 95% CI 1.38-3.02), 1 each in AKR1C2 and ESR1, and 1 in HSD17B6. Four SNPs were associated with inflammation risk, 2 in SRD5A1 (e.g., SRD5A1 rs248800: ORadj = 1.86, 95% CI 1.20-2.88) and 1 each in AKR1C2 and AKR1C3. MDR analysis identified a single AKR1C3 locus (rs2186174) as the best model for advanced fibrosis; while a 4-locus model with diabetes, AKR1C2 rs12414884, SRD5A1 rs6555406, and SRD5A1 rs248800 was best for inflammation. Conclusions: The consistency of our findings suggests AKR1C isoenzymes 2 and 3, and potentially SRD5A1, may play a role in progression of HCV-related liver disease in males. Future studies are needed to validate these findings and to assess if similar associations exist in females.
PMCID: PMC4214264  PMID: 25379136
Epidemiology; hepatology; endocrinology; infectious diseases; digestive system; carcinogenesis; genetics
13.  Physical Exercise is Associated with Less Neurocognitive Impairment Among HIV-Infected Adults 
Journal of neurovirology  2013;19(5):410-417.
Neurocognitive impairment (NCI) remains prevalent in HIV-infection. Randomized trials have shown that physical exercise improves NCI in non HIV-infected adults, but data on HIV-infected populations is limited. Community-dwelling HIV-infected participants (n=335) completed a comprehensive neurocognitive battery that was utilized to define both global and domain-specific NCI. Participants were divided into “Exercise” (n=83) and “No Exercise” (n=252) groups based on whether they self-reported engaging in any activity that increased heart rate in the last 72 hours or not. We also measured and evaluated a series of potential confounding factors, including demographics, HIV-disease characteristics, substance use and psychiatric comorbidities, and physical functioning. Lower rates of global NCI were observed among the Exercise group (15.7%) as compared to those in the No Exercise group (31.0%; p<.01). A multivariable logistic regression controlling for potential confounds (i.e., education, AIDS status, current CD4+ lymphocyte count, self-reported physical function, current depression) showed that being in the Exercise group remained significantly associated with lower global NCI (OR=2.63, p<.05). Similar models of domain-specific NCI showed that Exercise was associated with reduced impairment in working memory (p<.05) and speed of information processing (p<.05). The present findings suggest that HIV-infected adults who exercise are approximately half as likely to show NCI as compared to those who do not. Future longitudinal studies might be best suited to address causality and intervention trials in HIV-infected individuals will determine whether exercise can prevent or ameliorate NCI in this population.
PMCID: PMC3795938  PMID: 23934585
HIV/AIDS; Mild Neurocognitive Impairment; Physical Exercise; Cognition; Lifestyle; Neuropsychology
14.  Relation between Speech-in-Noise Threshold, Hearing Loss and Cognition from 40–69 Years of Age 
PLoS ONE  2014;9(9):e107720.
Healthy hearing depends on sensitive ears and adequate brain processing. Essential aspects of both hearing and cognition decline with advancing age, but it is largely unknown how one influences the other. The current standard measure of hearing, the pure-tone audiogram is not very cognitively demanding and does not predict well the most important yet challenging use of hearing, listening to speech in noisy environments. We analysed data from UK Biobank that asked 40–69 year olds about their hearing, and assessed their ability on tests of speech-in-noise hearing and cognition.
Methods and Findings
About half a million volunteers were recruited through NHS registers. Respondents completed ‘whole-body’ testing in purpose-designed, community-based test centres across the UK. Objective hearing (spoken digit recognition in noise) and cognitive (reasoning, memory, processing speed) data were analysed using logistic and multiple regression methods. Speech hearing in noise declined exponentially with age for both sexes from about 50 years, differing from previous audiogram data that showed a more linear decline from <40 years for men, and consistently less hearing loss for women. The decline in speech-in-noise hearing was especially dramatic among those with lower cognitive scores. Decreasing cognitive ability and increasing age were both independently associated with decreasing ability to hear speech-in-noise (0.70 and 0.89 dB, respectively) among the population studied. Men subjectively reported up to 60% higher rates of difficulty hearing than women. Workplace noise history associated with difficulty in both subjective hearing and objective speech hearing in noise. Leisure noise history was associated with subjective, but not with objective difficulty hearing.
Older people have declining cognitive processing ability associated with reduced ability to hear speech in noise, measured by recognition of recorded spoken digits. Subjective reports of hearing difficulty generally show a higher prevalence than objective measures, suggesting that current objective methods could be extended further.
PMCID: PMC4168235  PMID: 25229622
15.  A Field Evaluation of the Hardy TB MODS Kit™ for the Rapid Phenotypic Diagnosis of Tuberculosis and Multi-Drug Resistant Tuberculosis 
PLoS ONE  2014;9(9):e107258.
Even though the WHO-endorsed, non-commercial MODS assay offers rapid, reliable TB liquid culture and phenotypic drug susceptibility testing (DST) at lower cost than any other diagnostic, uptake has been patchy. In part this reflects misperceptions about in-house assay quality assurance, but user convenience of one-stop procurement is also important. A commercial MODS kit was developed by Hardy Diagnostics (Santa Maria, CA, USA) with PATH (Seattle, WA, USA) to facilitate procurement, simplify procedures through readymade media, and enhance safety with a sealing silicone plate lid. Here we report the results from a large-scale field evaluation of the MODS kit in a government service laboratory.
Methods & Findings
2446 sputum samples were cultured in parallel in Lowenstein-Jensen (LJ), conventional MODS and in the MODS kit. MODS kit DST was compared with conventional MODS (direct) DST and proportion method (indirect) DST. 778 samples (31.8%) were Mycobacterium tuberculosis culture-positive. Compared to conventional MODS the sensitivity, specificity, positive, and negative predictive values (95% confidence intervals) of the MODS Kit were 99.3% (98.3–99.8%), 98.3% (97.5–98.8%), 95.8% (94.0–97.1%), and 99.7% (99.3–99.9%). Median (interquartile ranges) time to culture-positivity (and rifampicin and isoniazid DST) was 10 (9–13) days for conventional MODS and 8.5 (7–11) for MODS Kit (p<0.01). Direct rifampicin and isoniazid DST in MODS kit was almost universally concordant with conventional MODS (97.9% agreement, 665/679 evaluable samples) and reference indirect DST (97.9% agreement, 687/702 evaluable samples).
MODS kit delivers performance indistinguishable from conventional MODS and offers a convenient, affordable alternative with enhanced safety from the sealing silicone lid. The availability in the marketplace of this platform, which conforms to European standards (CE-marked), readily repurposed for second-line DST in the near future, provides a fresh opportunity for improving equity of access to TB diagnosis and first and second-line DST in settings where the need is greatest.
PMCID: PMC4167337  PMID: 25225802
Consumption of dietary flavonoids has been associated with reduced mortality and risk of cardiovascular disease, partially by reducing triglyceridemia. We have previously reported that a grape seed procyanidin extract (GSPE) reduces postprandial triglyceridemia in normolipidemic animals signaling through the orphan nuclear receptor Small Heterodimer Partner (SHP) a target of the bile acid receptor Farnesoid X Receptor (FXR). Our aim was to elucidate whether FXR mediates the hypotriglyceridemic effect of procyanidins. In FXR-driven luciferase expression assays GSPE dose-dependently enhanced FXR activity in the presence of chenodeoxycholic acid. GSPE gavage reduced triglyceridemia in wild type mice but not in FXR-null mice, revealing FXR as an essential mediator of the hypotriglyceridemic actions of procyanidins in vivo. In the liver, GSPE down-regulated, in a FXR-dependent manner, the expression of the transcription factor Steroid Response Element Binding Protein 1 (SREBP1) and several SREBP1 target genes involved in lipogenesis, and upregulated ApoA5 expression. Altogether, our results indicate that procyanidins lower triglyceridemia following the same pathway as bile acids: activation of FXR, transient upregulation of SHP expression and subsequent downregulation of SREBP1 expression. This study adds dietary procyanidins to the arsenal of FXR ligands with potential therapeutic use to combat hypertriglyceridemia, type 2 diabetes and metabolic syndrome.
PMCID: PMC4142053  PMID: 19496086
Bile Acids; FXR; liver; procyanidins; SHP; SBARM; SREBP1; triglycerides
17.  Family-based interventions for substance misuse: a systematic review of systematic reviews—protocol 
Systematic Reviews  2014;3:90.
Worldwide, there are an estimated 15 million individuals with drug use disorders and over five times as many with alcohol use disorders (WHO 1:2, 2005). Most individuals with substance misuse have families who are affected. Initial scoping searches identified an expanse of broad and disparate studies and reviews on the family interventions for substance misuse. This systematic review of systematic reviews aims to bring together the expanse of research on the effectiveness of family-based interventions in substance misuse.
Initial scoping searches identified an expanse of broad and disparate studies and reviews on the family interventions for substance misuse. This systematic review of systematic reviews aims to bring together the expanse of research on the effectiveness of family-based interventions in substance misuse.
Extensive electronic and manual searches will be undertaken. Screening, data extraction and quality assessment will be undertaken by two reviewers with disagreements resolved through discussion.
The inclusion criteria will be that the study is a systematically undertaken review, the population is individuals with substance misuse problems and the interventions include a family-focused component. Reviews that focus on prevention rather than treatment will be excluded.
The reviews will be assessed for quality and relevance. The evidence from included systematic reviews will be mapped by focus of intervention (promoting engagement of user into treatment/joint involvement in treatment of user/treating family member in own right) for both adults and adolescents for drug and/or alcohol misusers to allow assessment of the density of available evidence. The higher-quality, up-to-date evidence for each domain will be identified and described, and conclusions will be drawn with limitations of the evidence highlighted.
This systematic review of systematic reviews will be an efficient and robust way of looking at the current state of the evidence in the field of family-based interventions for substance misuse.
It will evaluate all the available systematic-review-level literature to report on the effectiveness of family-based psychological interventions in improving substance-related outcomes and improving health and wellbeing of substance misusers and/or their families. This will inform future treatment policies and commissioning decisions.
In addition, it will identify areas of poor quality, inconsistency and gaps in the evidence base for family-based psychological interventions in substance misuse with respect to secondary evidence in order to inform future research.
Systematic review registration
PROSPERO CRD42014006834
PMCID: PMC4150116  PMID: 25128186
Families; Family therapy; Systematic review; Psychological interventions; Family interventions; Alcohol misuse; Drug misuse
18.  Constitutive Androstane Receptor Activation Decreases Plasma Apolipoprotein B–Containing Lipoproteins and Atherosclerosis in Low-Density Lipoprotein Receptor–Deficient Mice 
The goal of this study was to determine the impact of the nuclear receptor constitutive androstane receptor (CAR) on lipoprotein metabolism and atherosclerosis in hyperlipidemic mice.
Methods and Results
Low-density lipoprotein receptor–deficient (Ldlr−/−) and apolipoprotein E–deficient (ApoE−/−) mice fed a Western-type diet were treated weekly with the Car agonist 1,4-bis[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOP) or the vehicle only for 8 weeks. In Ldlr−/− mice, treatment with TCPOBOP induced a decrease in plasma triglyceride and intermediate-density lipoprotein/low-density lipoprotein cholesterol levels (≈30% decrease in both cases after 2 months, P<0.01). These mice also showed a significant reduction in the production of very-low-density lipoproteins associated with a decrease in hepatic triglyceride content and the repression of several genes involved in lipogenesis. TCPOBOP treatment also induced a marked increase in the very-low-density lipoprotein receptor in the liver, which probably contributed to the decrease in intermediate-density lipoprotein/low-density lipoprotein levels. Atherosclerotic lesions in the aortic valves of TCPOBOP-treated Ldlr−/− mice were also reduced (−60%, P<0.001). In ApoE−/− mice, which lack the physiological apoE ligand for the very-low-density lipoprotein receptor, the effect of TCPOBOP on plasma cholesterol levels and the development of atherosclerotic lesions was markedly attenuated.
CAR is a potential target in the prevention and treatment of hypercholesterolemia and atherosclerosis.
PMCID: PMC4104927  PMID: 21778422
atherosclerosis; lipoproteins; constitutive androstane receptor
20.  Association between Childhood Physical Abuse, Unprotected Receptive Anal Intercourse and HIV Infection among Young Men Who Have Sex with Men in Vancouver, Canada 
PLoS ONE  2014;9(6):e100501.
The association between childhood sexual abuse and HIV risk among men who have sex with men (MSM) is well established. However, no studies have examined the potential impact of other forms of childhood maltreatment on HIV incidence in this population.
We explored the impact of child physical abuse (CPA) on HIV seroconversion in a cohort of gay/bisexual men aged 15 to 30 in Vancouver, Canada. Cox proportional hazard models were used, controlling for confounders.
Among 287 participants, 211 (73.5%) reported experiencing CPA before the age of 17, and 42 (14.6%) reporting URAI in the past year. After a median of 6.6 years follow-up, 16 (5.8%) participants HIV-seroconverted. In multivariate analysis, CPA was significantly associated with HIV seroconversion (adjusted hazard ratio [AHR] = 4.89, 95% confidence interval (CI): 1.65–14.48), after controlling for potential confounders.
Our study uncovered a link between childhood physical violence and HIV incidence. Results highlight an urgent need for screening of young gay and bisexual men for histories of violence, and social and structural supports to prevent HIV transmission in this population.
PMCID: PMC4070929  PMID: 24963804
21.  Carbon dioxide hydrogenation to aromatic hydrocarbons by using an iron/iron oxide nanocatalyst 
The quest for renewable and cleaner energy sources to meet the rapid population and economic growth is more urgent than ever before. Being the most abundant carbon source in the atmosphere of Earth, CO2 can be used as an inexpensive C1 building block in the synthesis of aromatic fuels for internal combustion engines. We designed a process capable of synthesizing benzene, toluene, xylenes and mesitylene from CO2 and H2 at modest temperatures (T = 380 to 540 °C) employing Fe/Fe3O4 nanoparticles as catalyst. The synthesis of the catalyst and the mechanism of CO2-hydrogenation will be discussed, as well as further applications of Fe/Fe3O4 nanoparticles in catalysis.
PMCID: PMC4077464  PMID: 24991513
aromatic hydrocarbons; carbon dioxide reduction; heterogenous catalysis; iron/iron oxide nanocatalyst
22.  FXR-induced secretion of FGF15/19 inhibits CYP27 expression in cholangiocytes through p38 kinase pathway 
Cholangiocytes, bile duct lining cells, actively adjust the amount of cholesterol and bile acids in bile through expression of enzymes and channels involved in transportation and metabolism of the cholesterol and bile acids. Herein, we report molecular mechanisms regulating bile acid biosynthesis in cholangiocytes. Among the cytochrome p450 (Cyp) enzymes involved in bile acid biosynthesis, sterol 27-hydroxylase (Cyp27) that is the rate-limiting enzyme for the acidic pathway of bile acid biosynthesis expressed in cholangiocytes. Expression of other Cyp enzymes for the basic bile acid biosynthesis was hardly detected. The Cyp27 expression was negatively regulated by a hydrophobic bile acid through farnesoid X receptor (FXR), a nuclear receptor activated by bile acid ligands. Activated FXR exerted the negative effects by inducing an expression of fibroblast growth factor 15/19 (FGF15/19). Similar to its repressive function against cholesterol 7α-hydroxylase (Cyp7a1) expression in hepatocytes, secreted FGF15/19 triggered Cyp27 repression in cholangiocytes through interaction with its cognate receptor fibroblast growth factor receptor 4 (FGFR4). The involvements of FXR and FGFR4 for the bile acid-induced Cyp27 repression were confirmed in vivo using knockout mouse models. Different from the signaling in hepatocytes, wherein the FGF15/19-induced repression signaling is mediated by c-Jun N-terminal kinase (JNK), FGF15/19-induced Cyp27 repression in cholangiocytes was mediated by p38 kinase. Thus, the results collectively suggest that cholangiocytes may be able to actively regulate bile acid biosynthesis in cholangiocytes and even hepatocyte by secreting FGF15/19. We suggest the presence of cholangiocyte-mediated intrahepatic feedback loop in addition to the enterohepatic feedback loop against bile acid biosynthesis in the liver.
PMCID: PMC3967003  PMID: 24068255
Cholangiocyte; Cyp27; p38 kinase
23.  A Case-Controlled Study of Successful Aging in Older Adults with HIV 
The Journal of clinical psychiatry  2013;74(5):e417-e423.
There is a growing public health interest in the aging HIV-infected (HIV+) population, although there is a dearth of research on successful aging with HIV. This study aimed to understand the risk and protective factors associated with self-rated successful aging (SRSA) with HIV.
Cross-sectional, case-controlled.
HIV Neurobehavioral Research Program and the Stein Institute for Research on Aging at University of California, San Diego.
Eighty-three community-dwelling HIV+ and 83 demographically matched HIV-uninfected (HIV−) individuals, enrolled between 12/1/11 and 5/10/12, mean age of 59 years, primarily Caucasian males, 69% with AIDS, who had been living with an HIV diagnosis for 16 years. Diagnostic criteria for HIV/AIDS was obtained through a blood draw.
Participants provided ratings of SRSA as part of a comprehensive survey which included measures of physical and emotional functioning and positive psychological traits. Relationships between how the different variables related to SRSA were explored.
While SRSA was lower in the HIV+ individuals than their HIV− counterparts, 66% of adults with HIV reported scores of 5 or higher on a 10-point scale of SRSA. Despite worse physical and mental functioning and greater psychosocial stress among the HIV+ participants, the two groups had comparable levels of optimism, personal mastery, and social support. SRSA in HIV+ individuals was associated with better physical and emotional functioning and positive psychological factors, but not HIV disease status or negative life events.
Successful psychosocial aging is possible in older HIV+ individuals. Positive psychological traits such as resilience, optimism, and sense of personal mastery have stronger relationship with SRSA than duration or severity of HIV disease. Research on interventions to enhance these positive traits in HIV+ adults is warranted.
PMCID: PMC3683870  PMID: 23759460
HIV/AIDS; successful aging; physical function; emotional function; positive psychological factors; depression
To elaborate optimal anti-tuberculosis regimens following drug susceptibility testing (DST) to isoniazid (H) and rifampicin (R).
12 311 M. tuberculosis strains (National Health Institute of Peru 2007-2009) were classified in four groups according H and R resistance. In each group the sensitivity to ethambutol (E), pirazinamide (Z), streptomycin (S), kanamycin (Km), capreomycin (Cm), ciprofloxacin (Cfx), ethionamide (Eto), cicloserine (Cs) and p-amino salicilic acid (PAS) was determined. Based on resistance profiles, domestic costs, and following WHO guidelines, we elaborated and selected optimal putative regimens for each group. The potential efficacy (PE) variable was defined as the proportion of strains sensitive to at least three or four drugs for each regimen evaluated.
Selected regimes with the lowest cost, and highest PE of containing 3 and 4 effective drugs for TB sensitive to H and R were: HRZ (99,5%) and HREZ (99,1%), respectively; RZECfx (PE=98,9%) and RZECfxKm (PE=97,7%) for TB resistant to H; HZECfx (96,8%) and HZECfxKm (95,4%) for TB resistant to R; and EZCfxKmEtoCs (82.9%) for MDR-TB.
Based on resistance to H and R it was possible to select anti-tuberculosis regimens with high probability of success. This proposal is a feasible alternative to tackle tuberculosis in Peru where the access to rapid DST to H and R is improving progressively.
PMCID: PMC4000544  PMID: 23949502
Tuberculosis; Therapy; Diagnostic tests, routine; Isoniazid; Rifampin (source: MeSH NLM)
25.  Impact of Risk Factors for Specific Causes of Death in the First and Subsequent Years of Antiretroviral Therapy Among HIV-Infected Patients 
Among HIV-infected patients who initiated antiretroviral therapy (ART), patterns of cause-specific death varied by ART duration and were strongly related to age, sex, and transmission risk group. Deaths from non-AIDS malignancies were much more frequent than those from cardiovascular disease.
Background. Patterns of cause-specific mortality in individuals infected with human immunodeficiency virus type 1 (HIV-1) are changing dramatically in the era of antiretroviral therapy (ART).
Methods. Sixteen cohorts from Europe and North America contributed data on adult patients followed from the start of ART. Procedures for coding causes of death were standardized. Estimated hazard ratios (HRs) were adjusted for transmission risk group, sex, age, year of ART initiation, baseline CD4 count, viral load, and AIDS status, before and after the first year of ART.
Results. A total of 4237 of 65 121 (6.5%) patients died (median, 4.5 years follow-up). Rates of AIDS death decreased substantially with time since starting ART, but mortality from non-AIDS malignancy increased (rate ratio, 1.04 per year; 95% confidence interval [CI], 1.0–1.1). Higher mortality in men than women during the first year of ART was mostly due to non-AIDS malignancy and liver-related deaths. Associations with age were strongest for cardiovascular disease, heart/vascular, and malignancy deaths. Patients with presumed transmission through injection drug use had higher rates of all causes of death, particularly for liver-related causes (HRs compared with men who have sex with men: 18.1 [95% CI, 6.2–52.7] during the first year of ART and 9.1 [95% CI, 5.8–14.2] thereafter). There was a persistent role of CD4 count at baseline and at 12 months in predicting AIDS, non-AIDS infection, and non-AIDS malignancy deaths. Lack of viral suppression on ART was associated with AIDS, non-AIDS infection, and other causes of death.
Conclusions. Better understanding of patterns of and risk factors for cause-specific mortality in the ART era can aid in development of appropriate care for HIV-infected individuals and inform guidelines for risk factor management.
PMCID: PMC4073781  PMID: 24771333
HIV; cause-specific mortality; antiretroviral therapy

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