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.
inorganic nitrate; vascular function; pulse wave velocity
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.
Affective distress; Methamphetamine; Dependence; HIV; Longitudinal
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.
HIV/AIDS; Mild Neurocognitive Impairment; Physical Exercise; Cognition; Lifestyle; Neuropsychology
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.
BK-channel; microRNA; microRNA-9; methamphetamine; human immunodeficiency virus; HIV; neuron; brain
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.
Infectious disease; Disability; Substance use; Neuropsychology; AIDS-related Dementia
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.
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.
The feasibility, use, and acceptability of text messages to track methamphetamine use and promote antiretroviral treatment (ART) adherence among HIV-infected methamphetamine users was examined. From an ongoing randomized controlled trial, 30-day text response rates of participants assigned to the intervention (individualized texting for adherence building (iTAB), n = 20) were compared to those in the active comparison condition (n = 9). Both groups received daily texts assessing methamphetamine use, and the iTAB group additionally received personalized daily ART adherence reminder texts. Response rate for methamphetamine use texts was 72.9% with methamphetamine use endorsed 14.7% of the time. Text-derived methamphetamine use data was correlated with data from a structured substance use interview covering the same time period (P < 0.05). The iTAB group responded to 69.0% of adherence reminder texts; among those responses, 81.8% endorsed taking ART medication. Standardized feedback questionnaire responses indicated little difficulty with the texts, satisfaction with the study, and beliefs that future text-based interventions would be helpful. Moreover, most participants believed the intervention reduced methamphetamine use and improved adherence. Qualitative feedback regarding the intervention was positive. Future studies will refine and improve iTAB for optimal acceptability and efficacy. This trial is registered with ClinicalTrials.gov NCT01317277.
Using McDaniel & Einstein’s (2000) multi-process framework, the current study examined whether the length of prospective memory (PM) delay intervals as measured by the 2- and 15- minute subscales of the Memory for Intentions Screening Test (MIST) have differential predictive value for antiretroviral (ARV) adherence. Participants included 74 HIV-infected individuals whose ARV adherence was tracked with an electronic monitoring system. Participants were classified as “adherent” (n = 49) or “non-adherent” (n = 25) based on recorded pill bottle openings of ≥90% of prescribed doses over 30 days. An adherence group by MIST delay interval interaction was observed, such that non-adherent participants had worse performance on the 15-min, but not 2-min delay PM MIST subscales. The observed MIST 15- min delay effects were significantly more pronounced on time- versus event-cued PM trials. Long-delay time-based PM was predictive of non-adherence independent of demographics, mood state, self-reported adherence, and general cognitive functioning. Findings from this clinical study indicate that ARV non-adherence may be particularly associated with deficits in strategic cue monitoring over longer PM delays, which may inform interventions to improve adherence among persons living with HIV infection.
episodic memory; medication adherence; everyday functioning; neuropsychological assessment; executive functions; AIDS dementia complex
The present study assesses the impact of methamphetamine (METH) on antiretroviral (ART) adherence among HIV+ persons, as well as examines the contribution of neurocognitive impairment and other neuropsychiatric factors (i.e., major depressive disorder (MDD), Antisocial Personality Disorder (ASPD), and Attention Deficit Disorder (ADHD)) for ART nonadherence. We examined HIV+ persons with DSM-IV-diagnosed lifetime history of METH abuse/dependence (HIV+/METH+; n = 67) as compared to HIV+ participants with no history of METH abuse/dependence (HIV+/METH−; n = 50). Ancillary analyses compared these groups with a small group of HIV+/METH+ persons with current METH abuse/dependence (HIV+/CU METH+; n = 8). Nonadherence was defined as self-report of any skipped ART dose in the last four days. Neurocognitive functioning was assessed with a comprehensive battery, covering seven neuropsychological domains. Lifetime METH diagnosis was associated with higher rates of detectable levels of plasma and CSF HIV RNA. When combing groups (i.e., METH+ and METH− participants), univariate analyses indicated co-occurring ADHD, ASPD, and MDD predicted ART nonadherence (p’s<0.10; not lifetime METH status or neurocognitive impairment). A significant multivariable model including these variables indicated that only MDD uniquely predicted ART nonadherence after controlling for the other variables (p<0.05). Ancillary analyses indicated that current METH users (use within 30 days) were significantly less adherent (50% prevalence of nonadherence) than lifetime METH+ users and HIV+/METH-participants, and that neurocognitive impairment was associated with nonadherence (p’s<0.05). METH use disorders are associated with worse HIV disease outcomes and ART medication nonadherence. Interventions often target substance use behaviors alone to enhance antiretroviral treatment outcomes; however, in addition to targeting substance use behaviors, interventions to improve ART adherence may also need to address coexisting neuropsychiatric factors and cognitive impairment to improve ART medication taking.
HIV/AIDS; Cognition; Medication Adherence; Antiretroviral; Methamphetamine
The contribution of bipolar disorder (BD), a prevalent serious mental illness characterized by impulsivity and mood instability, to antiretroviral (ART) and psychiatric medication adherence among HIV-infected (HIV+) individuals is unknown. We examined medication adherence among 44 HIV+/BD+ persons as compared to 33 demographically- and medically-comparable HIV+/BD− persons. Classification of adherent (≥90%) or non-adherent (<90%) based on proportion of correctly taken doses over 30 days was determined using electronic medication monitoring devices. HIV+/BD+ persons were significantly less likely to be ART adherent (47.7%) as compared to HIV+/BD− (90.9%) persons. Within the HIV+/BD+ group, mean psychiatric medication adherence was significantly worse than ART medication adherence, although there was a significant correlation between ART and psychiatric adherence levels. Importantly, 30-day ART adherence was associated with plasma virologic response among HIV+/BD+ individuals. Given the high overlap of HIV and BD, and the observed medication adherence difficulties for these persons, specialized adherence improvement interventions are needed.
Medication Adherence; HIV/AIDS; Bipolar Disorder
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.
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.
HIV/AIDS; successful aging; physical function; emotional function; positive psychological factors; depression
Replicating HIV-1 in the brain is present in HIV encephalitis (HIVE) and microglial nodule encephalitis (MGNE) and is putatively linked with HIV-associated neurocognitive disorders (HAND). A clinico-neurovirological correlation was conducted to elucidate the relationship between brain viral load and clinical phenotype.
Subjects and assays
HIV gag/pol RNA and DNA copies were quantified with RT-PCR or PCR in 148 HAART-era brain specimens. Comparison to HAND, HIVE and MGNE and correlation with neuropsychological (NP) test scores were done using one-way ANOVA with Tukey-Kramer and Spearman’s tests respectively.
Brain HIV RNA was higher in subjects with HAND plus HIVE vs without HAND (delta = 2.48 log10 units, n = 27 vs 36, p < 0.001). In HAND without HIVE or MGNE, brain HIV RNA was not significantly different vs without HAND (p = 0.314). Worse NP scores correlated significantly with higher HIV RNA and interferon responses in brain specimens (p<0.001), but not with HIV RNA levels in premortem blood plasma (n = 114) or cerebrospinal fluid (n = 104). In subjects with MGNE, brain HIV RNA was slightly higher versus without MGNE (p<0.01), and much lower versus with HIVE (p<0.001).
Brain HIV RNA and to a lesser extent HIV DNA are correlated with worse NP performance in the 6 months before death. Linkage occurs primarily in patients with HIVE and MGNE; while on HAART these patients could obtain added NP improvement by further reducing brain HIV. Patients not in those groups are less certain to obtain added NP benefit.
Dementia; encephalitis; HIVE; neurocognitive disorders; HAND; Interferon
The frequency of neurodegenerative markers among long surviving HIV infected individuals is unknown, therefore, the present study investigated the frequency of α-synuclein, β-amyloid and HIV-associated brain pathology in the brains of older HIV infected individuals. We examined the substantia nigra of 73 clinically well-characterized HIV infected individuals aged 50 to 76 years from the National NeuroAIDS Tissue Consortium. We also examined the frontal and temporal cortical regions of a subset of 36 individuals. The brain regions were examined for the presence of α-synuclein, β-amyloid and HIV-associated brain pathology. Neuritic α-synuclein expression was found in 16% (12/73) of the substantia nigra of the HIV+ cases and none of the older control cases (0/18). β-amyloid deposits were prevalent and found in nearly all of the HIV+ cases (35/36). Despite these increases of degenerative pathology, HIV-associated brain pathology was present in only 10% of cases. Among older HIV+ adults HIV-associated brain pathology does not appear elevated; however, the frequency of both α-synuclein and β-amyloid is higher than that found in older healthy persons. The increased prevalence of α-synuclein and β-amyloid in the brains of older HIV-infected individuals may predict an increased risk of developing neurodegenerative disease.
HIV; Brain Pathology; Aging; Substantia Nigra; Cognition
Episodic memory deficits are common in HIV infection and bipolar disorder, but patient insight into such deficits remains unclear. Thirty-four HIV-infected individuals without bipolar disorder l(HIV+/BD−) and 47 HIV+ individuals with comorbid bipolar disorder (HIV+/BD+) were administered the Hopkins Verbal Learning Test-Revised and the Brief Visuospatial Memory Test-Revised to examine objective learning/memory functioning. Subjective memory complaints were assessed via the memory subscale of the Patient’s Assessment of Own Functioning Inventory. HIV+/BD+ individuals performed poorer on tests of visual learning and visual/verbal recall compared to HIV+/BD− participants (ps<0.05). Memory complaints only predicted verbal learning (at a trend level, p=0.10) and recall (p=0.03) among the HIV+/BD− individuals. Memory complaints were not associated with memory performance within the HIV+/BD+ group (ps>0.10). Memory complaints were associated with affective symptoms in both groups. These complaints were also predictive of immunosuppression, higher unemployment, and greater dependence on Activities of Daily Living among the HIV+/BD+ individuals (ps<0.05). Awareness of memory abilities was particularly poor among HIV+/BD+ individuals (i.e., objective learning/memory did not correspond to reported complaints), which has important implications for the capacity of these individuals to engage in error-monitoring and compensatory strategies in daily life. Memory complaints are associated with depressed mood regardless of group membership. Among HIV+/BD+ individuals, these complaints may also signify worse HIV disease status and problems with everyday functioning. Clinicians and researchers should be cognizant of what these complaints indicate in order to lead treatment most effectively; use of objective neurocognitive assessments may still be warranted when working with these populations.
Self report; Infectious Diseases; Affective Disorders; Episodic Memory; Cognition
Infection caused by intestinal parasites has significant public health consequences amongst children in the developing world. Street children are an under-studied group of society subjected to increased health risks when compared to their peers. To estimate the prevalence of intestinal parasitic infection and ascertain risk factors for parasitosis amongst this population, stool samples were collected from 258 children across four orphanages in three districts of Lima, Peru. Surveys were used to determine associations between risk factors and infection status. The prevalence of parasitic infection within the study sample was 66.3%, with 30.6% testing positive for pathogenic species. Entamoeba
coli was the most commonly detected parasite (41.9%) and Giardia lamblia was the most commonly detected pathogenic parasite (17.1%). Of the group 15.1% had helminth infection. When testing for association, age and BMI were risk factors for infection. A notable difference in prevalence (P < 0.00001) based on orphanage was observed, but the duration of residence in an orphanage was not a predictor for infection. A sub-analysis conducted amongst children who were given anti-parasitic treatment 5 months beforehand found no significant difference in parasitosis between those who had been given treatment and those who had not (P = 0.218). It is suggested that a single dose of albendazole alone may not be effective in combating long-term infection rates.
Peru; Homeless youth; Helminthiasis; Intestinal diseases; Parasitic; Cross-sectional studies
The acute and early stages of HIV infection (AEH) are characterized by substantial viral replication, immune activation, and alterations in brain metabolism. However, little is known about the prevalence and predictors of neurocognitive deficits and neuropsychiatric disturbances during this period. The present study examined the impact of demographic, HIV disease, and substance use factors on HIV-associated neurocognitive impairment and self-reported neuropsychiatric distress among 46 antiretroviral-naïve adults with median duration of infection of 75 days, relative to sample a of 21 HIV seronegative (HIV-) adults with comparable demographics and risk factors. Participants were administered a brief neurocognitive battery that was adjusted for demographics and assessed executive functions, memory, psychomotor speed, and verbal fluency, as well as the Profile of Mood States (POMS), a self-report measure of neuropsychiatric distress. Odds ratios revealed that AEH participants were nearly four times more likely than their seronegative counterparts to experience neurocognitive impairment, particularly in the areas of learning and information processing speed. Similarly, AEH was associated with a nearly five-fold increase in the odds of neuropsychiatric distress, most notably in anxiety and depression. Within the AEH sample, HIV-associated neurocognitive impairment was associated with problematic methamphetamine use and higher plasma HIV RNA levels, whereas neuropsychiatric distress was solely associated with high-risk alcohol use. Extending prior neuroimaging findings, results from this study indicate that HIV-associated neurocognitive impairment and neuropsychiatric distress are highly prevalent during AEH and are associated with high-risk substance use.
HIV; substance abuse; viral load; neuropsychiatry; AIDS dementia complex
To describe the prevalence of neurocognitive impairment (NCI) among early diagnosed and managed HIV-infected persons (HIV+) compared to HIV-negative controls.
We performed a cross-sectional study among 200 HIV+ and 50 matched HIV-uninfected (HIV−) military beneficiaries. HIV+ patients were categorized as earlier (<6 years of HIV, no AIDS-defining conditions, and CD4 nadir >200 cells/mm3) or later stage patients (n = 100 in each group); both groups were diagnosed early and had access to care. NCI was diagnosed using a comprehensive battery of standardized neuropsychological tests.
HIV+ patients had a median age of 36 years, 91% were seroconverters (median window of 1.2 years), had a median duration of HIV of 5 years, had a CD4 nadir of 319, had current CD4 of 546 cells/mm3, and 64% were on highly active antiretroviral therapy (initiated 1.3 years after diagnosis at a median CD4 of 333 cells/mm3). NCI was diagnosed among 38 (19%, 95% confidence interval 14%–25%) HIV+ patients, with a similar prevalence of NCI among earlier and later stage patients (18% vs 20%, p = 0.72). The prevalence of NCI among HIV+ patients was similar to HIV− patients.
HIV+ patients diagnosed and managed early during the course of HIV infection had a low prevalence of NCI, comparable to matched HIV-uninfected persons. Early recognition and management of HIV infection may be important in limiting neurocognitive impairment.
Pain interferes and disrupts attention. What is less clear is how pain affects performance on complex tasks, and the strategies used to ensure optimal outcomes. The aim of the current study was to examine the effect of pain on higher-order executive control processes involved in managing complex tasks. Sixty-two adult volunteers (40 female) completed two computer-based tasks: a breakfast making task and a word generation puzzle. Both were complex, involving executive control functions, including goal-directed planning and switching. Half of those recruited performed the tasks under conditions of thermal heat pain, and half with no accompanying pain. Whilst pain did not affect central performance on either task, it did have indirect effects. For the breakfast task, pain resulted in a decreased ability to multitask, with performance decrements found on the secondary task. However, no effects of pain were found on the processes thought to underpin this task. For the word generation puzzle, pain did not affect task performance, but did alter subjective accounts of the processes used to complete the task; pain affected the perceived allocation of time to the task, as well as switching perceptions. Sex differences were also found. When studying higher-order cognitive processes, pain-related interference effects are varied, and may result in subtle or indirect changes in cognition.
Difficulties with sustained attention have been found among both persons with HIV infection (HIV+) and bipolar disorder (BD). The authors examined sustained attention among 39 HIV+ individuals with BD (HIV+/BD+) and 33 HIV-infected individuals without BD (HIV+/BD−), using the Conners’ Continuous Performance Test–II (CPT–II). A Global Assessment of Functioning (GAF) score was also assigned to each participant as an overall indicator of daily functioning abilities. HIV+/BD+ participants had significantly worse performance on CPT–II omission errors, hit reaction time SE (Hit RT SE), variability of SE, and perseverations than HIV+/BD− participants. When examining CPT–II performance over the six study blocks, both HIV+/BD+ and HIV+/BD− participants evidenced worse performance on scores of commission errors and reaction times as the test progressed. The authors also examined the effect of current mood state (i.e., manic, depressive, euthymic) on CPT–II performance, but no significant differences were observed across the various mood states. HIV+/BD+ participants had significantly worse GAF scores than HIV+/BD− participants, which indicates poorer overall functioning in the dually-affected group; among HIV+/BD+ persons, significant negative correlations were found between GAF scores and CPT–II omission and commission errors, detectability, and perseverations, indicating a possible relationship between decrements in sustained attention and worse daily-functioning outcomes.
Tuberculosis control efforts are hampered by a mismatch in diagnostic technology: modern optimal diagnostic tests are least available in poor areas where they are needed most. Lack of adequate early diagnostics and MDR detection is a critical problem in control efforts.
The Microscopic Observation Drug Susceptibility (MODS) assay uses visual recognition of cording patterns from Mycobacterium tuberculosis (MTB) to diagnose tuberculosis infection and drug susceptibility directly from a sputum sample in 7–10 days with a low cost.
An important limitation that laboratories in the developing world face in MODS implementation is the presence of permanent technical staff with expertise in reading MODS.
We developed a pattern recognition algorithm to automatically interpret MODS results from digital images. The algorithm using image processing, feature extraction and pattern recognition determined geometrical and illumination features used in an object-model and a photo-model to classify TB-positive images. 765 MODS digital photos were processed. The single-object model identified MTB (96.9% sensitivity and 96.3% specificity) and was able to discriminate non-tuberculous mycobacteria with a high specificity (97.1% M. avium, 99.1% M. chelonae, and 93.8% M. kansasii). The photo model identified TB-positive samples with 99.1% sensitivity and 99.7% specificity.
This algorithm is a valuable tool that will enable automatic remote diagnosis using Internet or cellphone telephony. The use of this algorithm and its further implementation in a telediagnostics platform will contribute to both faster TB detection and MDR TB determination leading to an earlier initiation of appropriate treatment.
Estimates of the prevalence of lifetime suicidal ideation and attempt, and risks for new-onset suicidality, among HIV-infected (HIV+) individuals are not widely available in the era of modern combined antiretroviral treatment (cART).
Participants (n=1560) were evaluated with a comprehensive battery of tests that included the depression and substance use modules of the Composite International Diagnostic Interview (CIDI) and the Beck Depression Inventory-II (BDI-II) as part of a large prospective cohort study at six U.S. academic medical centers. Participants with possible lifetime depression (n=981) were classified into five categories: 1) no thoughts of death or suicide (n=352); 2) thoughts of death (n=224); 3) thoughts of suicide (n=99); 4) made a suicide plan (n=102); and 5) attempted suicide (n=204).
Twenty-six percent (405/1560) of participants reported lifetime suicidal ideation and 13% (204/1560) reported lifetime suicide attempt. Participants who reported suicidal thoughts or plans, or attempted suicide, reported higher scores on the BDI-II (p<0.0001), and higher rates of current major depressive disorder (p=0.01), than those who did not. Attempters reported higher rates of lifetime substance abuse (p=0.02) and current use of psychotropic medications (p=0.01) than non-attempters.
Study assessments focused on lifetime, rather than current, suicide. Data was not collected on the timing of ideation or attempt, frequency, or nature of suicide attempt.
High rates of lifetime suicidal ideation and attempt, and the relationship of past report with current depressed mood, suggests that mood disruption is still prevalent in HIV. Findings emphasize the importance of properly diagnosing and treating psychiatric comorbidities among HIV persons in the cART era.
HIV; depression; suicide
The apolipoprotein E (APOE) ε4 allele enhances cerebral accumulation of β-amyloid (Aβ) and is a major risk factor for sporadic Alzheimer’s disease (AD). We hypothesized that HIV-associated neurocognitive disorders (HAND) would be associated with the APOE ε4 genotype and cerebral Aβ deposition.
Clinico-pathological study of HIV-infected adults from four prospective cohorts in the U.S. National NeuroAIDS Tissue Consortium.
We used multivariable logistic regressions to model outcomes (Aβ plaques [immunohistochemistry] and HAND [standard criteria]) on predictors (APOE ε4 [allelic discrimination assay], older age [≥ 50 years], Aβ plaques, and their two-way interactions) and co-morbid factors.
Isocortical Aβ deposits generally occurred as diffuse plaques and mild to moderate amyloid angiopathy. Isocortical phospho-Tau-immunoreactive neurofibrillary lesions were sparse. The APOE ε4 and older age were independently associated with the presence of Aβ plaques (adjusted odds ratio [OR] 10.16 and 5.77 [95% confidence interval (CI) 2.89–35.76 and 1.91–17.48], P=0.0003 and 0.0019, respectively, n=96). The probability of HAND was increased in the presence of Aβ plaques among APOE ε4 carriers (adjusted OR 30.00 [95% CI 1.41–638.63], P=0.029, n=15), but not in non-ε4 carriers (n=57).
The APOE ε4 and older age increased the likelihood of cerebral Aβ plaque deposition in HIV-infected adults. Generally Aβ plaques in HIV brains were immunohistologically different from those in symptomatic AD brains. Nonetheless, Aβ plaques were associated with HAND among APOE ε4 carriers. The detection of APOE ε4 genotype and cerebral Aβ deposition biomarkers may be useful in identifying living HAND subjects who could benefit from Aβ-targeted therapies.
Apolipoprotein E; β-amyloid; HIV dementia; neurofibrillary pathology; phospho-Tau
During the last decade considerable attention has been focussed upon the development of new technologies and methodologies for detection of drug resistance in Mycobacterium tuberculosis. There is a growing acknowledgement that the redundancy in testing a full panel of first-line drugs is an unaffordable indulgence; since only resistance at baseline to either (or both) of the two most potent agents, isoniazid (H) and rifampicin (R), would usually prompt therapeutic modification there is a shift towards initial RH (or R alone for selected genotypic technologies) drug susceptibility testing (DST) followed, if necessary by further extended first and second line agent (currently phenotypic) DST. Most of the new drug susceptibility tests endorsed by the World Health Organization since 2007 deliver rapid RH (or R alone for selected genotypic technologies) DST. Targeting of patient groups with risk factors for drug resistance increases the proportion of tests that identify drug resistance, but in many settings at least as many patients with drug resistant disease will have no identifiable risk factors—equity of care demands that universal RH DST at baseline should be the goal. We review the bewildering array of choices facing TB program directors and attempt to provide objective information to help in deciding what tools may be best suited to different environments.