Longer duration of homelessness is associated with a lower likelihood of non-detectable plasma HIV-1 RNA viral load among people who use illicit drugs in a Canadian setting

Homelessness is common among people who use drugs (PWUD) and, for those living with HIV/AIDS, an important contributor to sub-optimal HIV treatment outcomes. This study aims to investigate the relationship between the duration of homelessness and the likelihood of plasma HIV-1 RNA viral load (VL) non-detectability among a cohort of HIV-positive PWUD. We used data from the ACCESS study, a long-running prospective cohort study of HIV-positive PWUD linked to comprehensive HIV clinical records including systematic plasma HIV-1 RNA VL monitoring. We estimated the longitudinal relationship between the duration of homelessness and the likelihood of exhibiting a non-detectable VL (i.e., <500?copies/mL plasma) using generalized linear mixed-effects modelling. Between May 1996 and June 2014, 922 highly active antiretroviral therapy-exposed participants were recruited and contributed 8188 observations. Of these, 4800 (59%) were characterized by non-detectable VL. Participants reported they were homeless in 910 (11%) interviews (median: six months, interquartile range: 6–12 months). A longer duration of homelessness was associated with lower odds of VL non-detectability (adjusted odds ratio?=?0.71 per six-month period of homelessness, 95% confidence interval: 0.60–0.83) after adjustment for age, ancestry, drug use patterns, engagement in addiction treatment, and other potential confounders. Longer durations of episodes of homelessness in this cohort of HIV-positive illicit drug users were associated with a lower likelihood of plasma VL non-detectability. Our findings suggest that interventions that seek to promptly house homeless individuals, such as Housing First approaches, might assist in maximizing the clinical and public health benefits of antiretroviral therapy among people living with HIV/AIDS.     

Postoperative Changes In The Tensor Fascia Lata Muscle After Using The Modified Anterolateral Approach For Total Hip Arthroplasty

The modified Watson-Jones approach to the hip has been described as a minimally invasive approach with the potential for fewer postoperative complications than the traditional approach. Because the approach relies on an intermuscular rather than an internervous plane, there is potential for injury to the superior gluteal nerve. The aim of this study was to evaluate incidence of tensor fascia lata (TFL) denervation in patients undergoing this approach. Twenty-six patients underwent total hip arthroplasty (THA) using a modified anterolateral approach. Postoperative MRIs were analyzed for signs of muscle denervation including atrophy, hypertrophy and fat replacement. At a median follow-up of 9.3 months, 74% of patients exhibited either atrophy or hypertrophy of the TFL and 42% exhibited fat replacement on MRI.     

MR Spectroscopic Evidence of Brain Injury in the Non-Diagnosed Collision Sport Athlete

With growing evidence of long-term neurological damage in individuals enduring repetitive head trauma, it is critical to detect lower-level damage accumulation for the early diagnosis of injury in at-risk populations. Proton magnetic resonance spectroscopic scans of the dorsolateral prefrontal cortex and primary motor cortex were collected from high school American (gridiron) football athletes, prior to and during their competition seasons. Although no concussions were diagnosed, significant metabolic deviations from baseline and non-collision sport controls were revealed. Overall the findings indicate underlying biochemical changes, consequential to repetitive hits, which have previously gone unnoticed due to a lack of traditional neurological symptoms.     

Exploring frontal asymmetry using functional near-infrared spectroscopy: a preliminary study of the effects of social anxiety during interaction and performance tasks

Preliminary studies examining brain function associated with social anxiety suggest the possibility of right-sided prefrontal activation associated with phobic stimulation. Although most existing neuroimaging techniques preclude participants from engaging in ecologically valid social tasks during assessment, functional near-infrared spectroscopy (fNIRS) is a promising new technique that permits such assessment. The present study investigated the utility of the fNIRS procedure and explored frontal asymmetry during in vivo social challenge tasks among female undergraduate students who scored in top and bottom percentiles on a social anxiety screening measure. Results revealed that participants in both groups experienced a significant increase in concentration of blood volume and oxygenated hemoglobin in the right hemisphere compared to the left hemisphere while giving a speech. Non-hemispheric effects were also observed. In addition, the high anxiety group showed a non-significant trend toward greater right frontal activity than the low anxiety group. This study highlights the utility of the fNIRS device in successfully assessing real-time changes in cerebrovascular response as a function of naturalistic social behavior, and supports the potential utility of this technology in the study of the neurophysiology of social anxiety.     

Breathe easy: 5 steps to better breathing with your metered-dose inhaler (MDI)

Proper use of the metered-dose inhaler (MDI) is essential for medications to prevent and treat acute asthma exacerbations. This training video teaches children and clinicians correct technique for MDI use.     

Time‐dependent effects of isoflurane and dexmedetomidine on functional connectivity,spectral characteristics,and spatial distribution of spontaneous BOLD fluctuations

Anesthesia is often necessary to perform fMRI experiments in the rodent model; however, commonly used anesthetic protocols may manifest changing brain conditions over the duration of the study. This possibility was explored in the current work. Eleven rats were anesthetized with 2% isoflurane anesthesia; four rats were anesthetized for a short period (30 min, simulating induction and fMRI setup) and seven rats were anesthetized for a long period (3 h, simulating surgical preparation). Following the initial anesthetic period, isoflurane was discontinued, and a dexmedetomidine bolus (0.025 mg/kg) and continuous subcutaneous infusion (0.05 mg/kg/h) were administered. Blood‐oxygen‐level dependent resting state imaging was performed every 30 min from 0.75 h post dexmedetomidine bolus until 5.75 h post‐bolus. Evaluation of power spectra obtained from time courses in the primary somatosensory cortex revealed, in general, a monotonic increase in low‐frequency power (0.05–0.3 Hz) in both groups over the duration of resting state imaging. Greater low‐band spectral power (0.05–0.15 Hz) is present in the short isoflurane group for the first 2.75 h, but the spectra become highly uniform at 3.25 h. The emergence of a ~0.18 Hz peak, beginning at the 3.75 h time point, exists in both groups and evolves similarly, increasing in strength as the duration of dexmedetomidine sedation (and time since isoflurane cessation) extends. In the long isoflurane group only, bilateral functional connectivity strengthens with anesthetic duration, and correlation is linearly linked to low‐band spectral power. Convergence of connectivity and spectral metrics between the short and long isoflurane groups occurs at ~3.25 h, suggesting the effects of isoflurane have subsided. Researchers using dexmedetomidine following isoflurane for functional studies should be aware of the duration specific effects of the pre‐scan isoflurane durations as well as the continuing influences of long‐term imaging under dexmedetomidine. Copyright © 2014 John Wiley & Sons, Ltd.     

Future Directions to Establish Lipoprotein(a) as a Treatment for Atherosclerotic Cardiovascular Disease

In both epidemiologic and genetic studies, increased levels of Lp(a) have been associated with increased risk for cardiovascular diseases as well as aortic stenosis. However, until recently, it has been difficult to lower levels of Lp(a). Diet and lifestyle have little effect on plasma levels of Lp(a) which are mainly genetically determined. Emerging therapeutic agents which have recently become available, or which are undergoing clinical trials, can significantly lower Lp(a) levels. Studies with these agents will hopefully be able to provide more direct information whether reductions in Lp(a) will reduce CVD events independently of reduction in LDL-cholesterol levels.