3,206 research outputs found
Facilitators and Barriers to Prescribing PreExposure Prophylaxis (PrEP) for the Prevention of HIV
Background:
What is PrEP and who gets it?
PrEP is the use of medication by individuals to prevent HIV contraction, approved in 2012 after demonstrating safety and efficacy in the iPrEx study and Partners PrEP2 trials.
HIV infection risk is 92% lower in patients using PrEP.
Truvada®, a combination of tenofovir and emtricitabine taken orally daily, is the only approved PrEP regimen and is intended to compliment other prevention strategies such as condoms.
HIV negative-individuals at risk for exposure to HIV have been identified as men who have sex with men (MSM), IV drug users, heterosexuals who have unprotected sex with partners of unknown HIV status, and those in serodiscordant relationships.
Barriers to PrEP Implementation
PrEP is effective when patients adhere; however, both the medical community and some high-risk populations have been slow to adopt it as an HIV prevention strategy.
Surveys have shown clinicians perceived barriers to PrEP such as adverse side effects, viral drug resistance, increased high-risk behavior, cost, and training.
HIV in Vermont
New diagnoses of HIV among Vermont residents has remained relatively stable over the last twenty years.
Vermont CARES, a non-profit, offers free and anonymous HIV tests and in-person risk-reduction counseling. Clients are increasingly asking about PrEP as a prevention strategy, but the response from the medical community is difficult to ascertain.https://scholarworks.uvm.edu/comphp_gallery/1235/thumbnail.jp
MicroRNA profiling reveals marker of motor neuron disease in ALS models
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder marked by the loss of motor neurons (MNs) in the brain and spinal cord, leading to fatally debilitating weakness. Because this disease predominantly affects MNs, we aimed to characterize the distinct expression profile of that cell type to elucidate underlying disease mechanisms and to identify novel targets that inform on MN health during ALS disease time course. microRNAs (miRNAs) are short, noncoding RNAs that can shape the expression profile of a cell and thus often exhibit cell-type-enriched expression. To determine MN-enriched miRNA expression, we used Cre recombinase-dependent miRNA tagging and affinity purification in mice. By defining thein vivomiRNA expression of MNs, all neurons, astrocytes, and microglia, we then focused on MN-enriched miRNAs via a comparative analysis and found that they may functionally distinguish MNs postnatally from other spinal neurons. Characterizing the levels of the MN-enriched miRNAs in CSF harvested from ALS models of MN disease demonstrated that one miRNA (miR-218) tracked with MN loss and was responsive to an ALS therapy in rodent models. Therefore, we have used cellular expression profiling tools to define the distinct miRNA expression of MNs, which is likely to enrich future studies of MN disease. This approach enabled the development of a novel, drug-responsive marker of MN disease in ALS rodents.SIGNIFICANCE STATEMENTAmyotrophic lateral sclerosis (ALS) is a neurodegenerative disease in which motor neurons (MNs) in the brain and spinal cord are selectively lost. To develop tools to aid in our understanding of the distinct expression profiles of MNs and, ultimately, to monitor MN disease progression, we identified small regulatory microRNAs (miRNAs) that were highly enriched or exclusive in MNs. The signal for one of these MN-enriched miRNAs is detectable in spinal tap biofluid from an ALS rat model, where its levels change as disease progresses, suggesting that it may be a clinically useful marker of disease status. Furthermore, rats treated with ALS therapy have restored expression of this MN RNA marker, making it an MN-specific and drug-responsive marker for ALS rodents.</jats:p
Energy-Related Indicators and Breast Cancer Risk among White and Black Women
Energy-related indicators, including physical activity, energy intake, body mass index (BMI) and adult weight change, have been linked to breast cancer risk. Very few studies of these associations have been conducted among black women, therefore we used the Nashville Breast Health Study (NBHS) to determine whether similar effects were seen in black and white women. The NBHS is a population-based case-control study of breast cancer among women age 25 to 75 years conducted between 2001 and 2010 in and around the Nashville Metropolitan area. Telephone interviews and self-administered food frequency questionnaires were completed with 2,614 incident breast cancer cases ascertained through hospitals and the statewide cancer registry, and 2,306 controls selected using random digit dialing. Among premenopausal white and black women, there was little effect of adult exercise or other energy-related indicators on breast cancer risk, regardless of tumor estrogen receptor (ER) status. The beneficial effect of adult exercise on postmenopausal breast cancer appeared to be comparable between white and black women (highest tertile relative to none - white odds ratio [OR] 0.8, 95% confidence interval [CI] 0.6-1.0, p for trend=0.05; black OR 0.7, 95% CI 0.4-1.1, p for trend=0.07); however, among black women the reduction was limited to those with ER-positive disease. White and black women should be encouraged to engage in more physical activity to reduce their risk of postmenopausal breast cancer
Psychosocial concerns and needs of cancer survivors treated at a comprehensive cancer center and a community safety net hospital
The number of cancer survivors in the United States is expected to grow to 18 million by 2020 because of improved cancer treatment outcomes and the aging of the population.[1] Many cancer survivors are at increased risk for cancer recurrence and other adverse long-term physical and psychosocial conditions.[2-5] Disparities in survival are associated with inadequate or no health insurance coverage because individuals are more likely to be diagnosed with cancer at later stages,[6] and higher incidence for some cancers among African Americans.[7] Few studies have examined psychosocial health disparities during cancer survivorship,[8-13] and little is known about how psychosocial factors subsequent to diagnosis affect survival and long-term outcomes. [4,14] While clinical care relevant to survivorship outcomes is advancing, [15, 16] optimal practices for preparing survivors for treatment and transitioning off treatment have yet to be defined. [11, 15, 17] Furthermore, guidance is needed for serving minority and underserved survivor populations where health disparities exist.[7] More data are needed about incidence of adverse outcomes and their determinants, overall and in disparity populations to inform development of best practices for preventive interventions. The purpose of this study was to identify similarities and differences among two groups of survivors in (1) sources of information at time of cancer diagnosis, (2) sources of support used during and after treatment, (3) stressors and challenges during and after treatment, and (4) coping strategies[18] used during and following cancer treatment. These factors might be associated with health services use,[19] and with survivorship disparities.[20] One group was treated at Vanderbilt-Ingram Cancer Center (VICC), an NCI-designated comprehensive cancer center, and the other at Meharry Medical College (MMC), its partner medical setting that serves patients who are mostly publicly-insured and uninsured. Secondary analysis of data from focus group participants was undertaken to address the four study topics and to guide future development of interventions tailored to preferences and needs of diverse survivors
A Dendritic Guidance Receptor Complex Brings Together Distinct Actin Regulators to Drive Efficient F-Actin Assembly and Branching
Proper morphogenesis of dendrites plays a fundamental role in the establishment of neural circuits. The molecular mechanism by which dendrites grow highly complex branches is not well understood. Here, using the C. elegans PVD neuron, we demonstrate that high-order dendritic branching requires actin polymerization driven by coordinated interactions between two membrane proteins, DMA-1 and HPO-30, and with their cytoplasmic interactors, the RacGEF TIAM-1 and the actin nucleation promotion factor WAVE Regulatory Complex (WRC). The dendrite branching receptor DMA-1 directly binds to the PDZ domain of TIAM-1, while the claudin-like protein HPO-30 directly interacts with the WRC. On dendrites, DMA-1 and HPO-30 form a receptor-associated signaling complex to bring TIAM-1 and the WRC to close proximity, leading to elevated assembly of F-actin needed to drive high-order dendrite branching. The synergistic activation of F-actin assembly by scaffolding distinct actin regulators might represent a general mechanism in promoting complex dendrite arborization
VarScan 2: Somatic mutation and copy number alteration discovery in cancer by exome sequencing
Cancer is a disease driven by genetic variation and mutation. Exome sequencing can be utilized for discovering these variants and mutations across hundreds of tumors. Here we present an analysis tool, VarScan 2, for the detection of somatic mutations and copy number alterations (CNAs) in exome data from tumor–normal pairs. Unlike most current approaches, our algorithm reads data from both samples simultaneously; a heuristic and statistical algorithm detects sequence variants and classifies them by somatic status (germline, somatic, or LOH); while a comparison of normalized read depth delineates relative copy number changes. We apply these methods to the analysis of exome sequence data from 151 high-grade ovarian tumors characterized as part of the Cancer Genome Atlas (TCGA). We validated some 7790 somatic coding mutations, achieving 93% sensitivity and 85% precision for single nucleotide variant (SNV) detection. Exome-based CNA analysis identified 29 large-scale alterations and 619 focal events per tumor on average. As in our previous analysis of these data, we observed frequent amplification of oncogenes (e.g., CCNE1, MYC) and deletion of tumor suppressors (NF1, PTEN, and CDKN2A). We searched for additional recurrent focal CNAs using the correlation matrix diagonal segmentation (CMDS) algorithm, which identified 424 significant events affecting 582 genes. Taken together, our results demonstrate the robust performance of VarScan 2 for somatic mutation and CNA detection and shed new light on the landscape of genetic alterations in ovarian cancer
Radio loud AGN and the L_X - \sigma relation of galaxy groups and clusters
We use the ROSAT All-Sky Survey to study the X-ray properties of a sample of
625 groups and clusters of galaxies selected from the Sloan Digital Sky Survey.
We stack clusters with similar velocity dispersions and investigate whether
their average X-ray luminosities and surface brightness profiles vary with the
radio activity level of their central galaxies. We find that at a given value
of , clusters with a central radio AGN have more concentrated X-ray
surface brightness profiles, larger central galaxy masses, and higher X-ray
luminosities than clusters with radio-quiet central galaxies. The enhancement
in X-ray luminosity is more than a factor of two, is detected with better than
6 significance, and cannot be explained by X-ray emission from the
radio AGN itself. This difference is largely due to a subpopulation of
radio-quiet, high velocity dispersion clusters with low mass central galaxies.
These clusters are underluminous at X-ray wavelengths when compared to
otherwise similar clusters where the central galaxy is radio-loud, more
massive, or both.Comment: Section 5.2 is updated, more discussion on the dependence of L_X -
\sigma relation on the stellar mass of BCG
Differential effects of EPA vs. DHA on postprandial vascular function and the plasma oxylipin profile in men
Our objective was to investigate the impact of EPA versus DHA, on arterial stiffness and reactivity, and underlying mechanisms (with a focus on plasma oxylipins), in the postprandial state. In a 3-arm cross-over acute test meal trial men (n=26, 35-55y) at increased CVD risk, received a high fat (42.4g) test meal providing 4.16 g of EPA or DHA or control oil in random order. At 0 h and 4 h, blood samples were collected to quantify plasma fatty acids, LCn-3PUFAs derived oxylipins, nitrite and hydrogen sulfide and serum lipids and glucose. Vascular function was assessed using blood pressure, Reactive Hyperaemia Index (RHI), Pulse Wave Velocity and Augmentation Index (AIx). The DHA-rich oil significantly reduced AIx by 13% (P=0.047) with the decrease following EPA-rich oil intervention not reaching statistical significance. Both interventions increased EPA and DHA derived oxylipins in the acute postprandial state, with an (1.3 fold) increase in 19,20-DiHDPA evident after DHA intervention (P < 0.001). In conclusion, a single dose of DHA significantly improved postprandial arterial stiffness as assessed by AIx, which if sustained would be associated with a significant decrease in CVD risk. The observed increases in oxylipins provide a mechanistic insight for the AIx effect
Complex thermal expansion properties in a molecular honeycomb lattice
[FeL3][BF4]2·xH2O (L = 3-(pyrazinyl)-1H-pyrazole) shows negative thermal expansion between 150–240 K but positive thermal expansion at 240–300 K, linked to rearrangement of anions and water molecules within pores in the lattice.</p
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