23 research outputs found

    Assessing the structure-function relationships of the apolipoprotein(a) kringle IV sub-type 10 domain

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    Elevated plasma lipoprotein(a) (Lp(a)) is the most prevalent heritable risk factor in the development of cardiovascular disease. The apolipoprotein(a) (apo(a)) component of Lp(a) is strongly implicated in the pathogenicity of Lp(a). It is hypothesized that the inflammatory potential of Lp(a)/apo(a) is mediated by the lysine binding ability of the apo(a) kringle IV10 (KIV10) domain, along with its covalently bound oxidized phospholipid (oxPL). Using targeted mutagenesis, two novel null alleles for the LPA gene that generate non-secretable apo(a) species have been identified, resulting from amino acid substitutions in the KIV10 domain. A potential mechanism by which KIV10 oxPL modification is enriched was identified. Finally, RNA-Seq was utilized to demonstrate gene regulation in macrophage-like cells in response to the lysine binding function and covalent oxPL of the KIV10 domain. It was determined that the lysine binding ability and covalent oxPL of apo(a) KIV10 are both implicated in vascular cell inflammation and atherosclerosis

    Loss of LKB1-NUAK1 signalling enhances NF-ÎşB activity in a spheroid model of high-grade serous ovarian cancer

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    High-grade serous ovarian cancer (HGSOC) is an aggressive malignancy often diagnosed at an advanced stage. Although most HGSOC patients respond initially to debulking surgery combined with cytotoxic chemotherapy, many ultimately relapse with platinum-resistant disease. Thus, improving outcomes requires new ways of limiting metastasis and eradicating residual disease. We identified previously that Liver kinase B1 (LKB1) and its substrate NUAK1 are implicated in EOC spheroid cell viability and are required for efficient metastasis in orthotopic mouse models. Here, we sought to identify additional signalling pathways altered in EOC cells due to LKB1 or NUAK1 loss-of-function. Transcriptome analysis revealed that inflammatory signalling mediated by NF-ÎşB transcription factors is hyperactive due to LKB1-NUAK1 loss in HGSOC cells and spheroids. Upregulated NF-ÎşB signalling due to NUAK1 loss suppresses reactive oxygen species (ROS) production and sustains cell survival in spheroids. NF-ÎşB signalling is also activated in HGSOC precursor fallopian tube secretory epithelial cell spheroids, and is further enhanced by NUAK1 loss. Finally, immunohistochemical analysis of OVCAR8 xenograft tumors lacking NUAK1 displayed increased RelB expression and nuclear staining. Our results support the idea that NUAK1 and NF-ÎşB signalling pathways together regulate ROS and inflammatory signalling, supporting cell survival during each step of HGSOC pathogenesis. We propose that their combined inhibition may be efficacious as a novel therapeutic strategy for advanced HGSOC

    Selection on stability across ecological scales

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    Much of the focus in evolutionary biology has been on the adaptive differentiation among organisms. It is equally important to understand the processes that result in similarities of structure among systems. Here, we discuss examples of similarities occurring at different ecological scales, from predator–prey relations (attack rates and handling times) through communities (food-web structures) to ecosystem properties. Selection among systemic configurations or patterns that differ in their intrinsic stability should lead generally to increased representation of relatively stable structures. Such nonadaptive, but selective processes that shape ecological communities offer an enticing mechanism for generating widely observed similarities, and have sparked new interest in stability properties. This nonadaptive systemic selection operates not in opposition to, but in parallel with, adaptive evolution

    Atherogenic Lipoprotein(a) Increases Vascular Glycolysis, Thereby Facilitating Inflammation and Leukocyte Extravasation

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    Rationale: Patients with elevated levels of lipoprotein(a) [Lp(a)] are hallmarked by increased metabolic activity in the arterial wall on positron emission tomography/computed tomography, indicative of a proinflammatory state. Objective: We hypothesized that Lp(a) induces endothelial cell inflammation by rewiring endothelial metabolism. Methods and Results: We evaluated the impact of Lp(a) on the endothelium and describe that Lp(a), through its oxidized phospholipid content, activates arterial endothelial cells, facilitating increased transendothelial migration of monocytes. Transcriptome analysis of Lp(a)-stimulated human arterial endothelial cells revealed upregulation of inflammatory pathways comprising monocyte adhesion and migration, coinciding with increased 6-phophofructo-2-kinase/fructose-2,6-biphosphatase (PFKFB)-3-mediated glycolysis. ICAM (intercellular adhesion molecule)-1 and PFKFB3 were also found to be upregulated in carotid plaques of patients with elevated levels of Lp(a). Inhibition of PFKFB3 abolished the inflammatory signature with concomitant attenuation of transendothelial migration. Conclusions: Collectively, our findings show that Lp(a) activates the endothelium by enhancing PFKFB3-mediated glycolysis, leading to a proadhesive state, which can be reversed by inhibition of glycolysis. These findings pave the way for therapeutic agents targeting metabolism aimed at reducing inflammation in patients with cardiovascular disease

    Design, baseline characteristics, and retention of African American light smokers into a randomized trial involving biological data

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    <p>Abstract</p> <p>Background</p> <p>African Americans experience significant tobacco-related health disparities despite the fact that over half of African American smokers are light smokers (use ≤10 cigarettes per day). African Americans have been under-represented in smoking cessation research, and few studies have evaluated treatment for light smokers. This paper describes the study design, measures, and baseline characteristics from <it>Kick It at Swope III </it>(KIS-III), the first treatment study of bupropion for African American light smokers.</p> <p>Methods</p> <p>Five hundred forty African American light smokers were randomly assigned to receive bupropion (150mg bid) (n = 270) or placebo (n = 270) for 7 weeks. All participants received written materials and health education counseling. Participants responded to survey items and provided blood samples for evaluation of phenotype and genotype of CYP2A6 and CYP2B6 enzymes involved in nicotine and bupropion metabolism. Primary outcome was cotinine-verified 7-day point prevalence smoking abstinence at Week 26 follow-up.</p> <p>Results</p> <p>Of 2,628 individuals screened, 540 were eligible, consented, and randomized to treatment. Participants had a mean age of 46.5 years and 66.1% were women. Participants smoked an average of 8.0 cigarettes per day, had a mean exhaled carbon monoxide of 16.4ppm (range 1-55) and a mean serum cotinine of 275.8ng/ml. The mean Fagerström Test for Nicotine Dependence was 3.2, and 72.2% of participants smoked within 30 minutes of waking. The average number of quit attempts in the past year was 3.7 and 24.2% reported using pharmacotherapy in their most recent quit attempt. Motivation and confidence to quit were high.</p> <p>Conclusion</p> <p>KIS-III is the first study designed to examine both nicotine and bupropion metabolism, evaluating CYP2A6 and CYP2B6 phenotype and genotype in conjunction with psychosocial factors, in the context of treatment of African American light smokers. Of 1629 smokers screened for study participation, only 18 (1.1%) were ineligible to participate in the study because they refused blood draws, demonstrating the feasibility of recruiting and enrolling African American light smokers into a clinical treatment trial involving biological data collection and genetic analyses. Future evaluation of individual factors associated with treatment outcome will contribute to advancing tailored tobacco use treatment with the goal of enhancing treatment and reducing health disparities for African American light smokers.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="URL">NCT00666978</a></p

    Specific treatment of problems of the spine (STOPS): design of a randomised controlled trial comparing specific physiotherapy versus advice for people with subacute low back disorders

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    <p>Abstract</p> <p>Background</p> <p>Low back disorders are a common and costly cause of pain and activity limitation in adults. Few treatment options have demonstrated clinically meaningful benefits apart from advice which is recommended in all international guidelines. Clinical heterogeneity of participants in clinical trials is hypothesised as reducing the likelihood of demonstrating treatment effects, and sampling of more homogenous subgroups is recommended. We propose five subgroups that allow the delivery of specific physiotherapy treatment targeting the pathoanatomical, neurophysiological and psychosocial components of low back disorders. The aim of this article is to describe the methodology of a randomised controlled trial comparing specific physiotherapy treatment to advice for people classified into five subacute low back disorder subgroups.</p> <p>Methods/Design</p> <p>A multi-centre parallel group randomised controlled trial is proposed. A minimum of 250 participants with subacute (6 weeks to 6 months) low back pain and/or referred leg pain will be classified into one of five subgroups and then randomly allocated to receive either physiotherapy advice (2 sessions over 10 weeks) or specific physiotherapy treatment (10 sessions over 10 weeks) tailored according to the subgroup of the participant. Outcomes will be assessed at 5 weeks, 10 weeks, 6 months and 12 months following randomisation. Primary outcomes will be activity limitation measured with a modified Oswestry Disability Index as well as leg and back pain intensity measured on separate 0-10 Numerical Rating Scales. Secondary outcomes will include a 7-point global rating of change scale, satisfaction with physiotherapy treatment, satisfaction with treatment results, the Sciatica Frequency and Bothersomeness Scale, quality of life (EuroQol-5D), interference with work, and psychosocial risk factors (Orebro Musculoskeletal Pain Questionnaire). Adverse events and co-interventions will also be measured. Data will be analysed according to intention to treat principles, using linear mixed models for continuous outcomes, Mann Whitney U tests for ordinal outcomes, and Chi-square, risk ratios and risk differences for dichotomous outcomes.</p> <p>Discussion</p> <p>This trial will determine the difference in outcomes between specific physiotherapy treatment tailored to each of the five subgroups versus advice which is recommended in guidelines as a suitable treatment for most people with a low back disorder.</p> <p>Trial registration</p> <p>Australia and New Zealand Clinical Trials Register (ANZCTR): <a href="http://www.anzctr.org.au/ACTRN12609000834257.aspx">ACTRN12609000834257</a>.</p

    Motivational enhancement to improve adherence to positive airway pressure in patients with obstructive sleep apnea: A randomized controlled trial

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    BACKGROUND: Obstructive sleep apnea (OSA) is associated with a variety of medical conditions. Positive airway pressure (PAP) is an effective treatment for improving sleep, yet adherence rates are low. The aim of the current study is to test two treatments versus standard care in improving adherence to PAP. METHOD: Two hundred twenty-seven patients with OSA were randomized to standard care (SC), education (ED) and motivational enhancement therapy (MET). Adherence was measured objectively and the first week of adherence (prior to the intervention) was used as an a priori moderator of the effect of the various interventions. Mediators of treatment response were also examined using theory-based measures of decisional balance and self-efficacy. RESULTS: Adherence declined over time for all three groups. There was a significant interaction between level of adherence during the first week of treatment and treatment group. Those who had moderate levels of adherence during their first week of PAP were more likely to adhere to treatment at follow-up if they had MET; those who had high levels of adherence during their first week of PAP were more likely to adhere to treatment at follow-up if they had ED. MET treatment increased the perception of the positive aspects of PAP, but ED did not. CONCLUSIONS: Initial adherence to positive airway pressure could help guide subsequent treatment plans. The results also support social cognitive theory in that educational approaches might be best suited for those who are ready for change whereas more motivational approaches might be best for those who are ambivalent about change. CITATION: Aloia MS; Arnedt JT; Strand M; Millman RP; Borrelli B. Motivational enhancement to improve adherence to positive airway pressure in patients with obstructive sleep apnea: a randomized controlled trial. SLEEP 2013;36(11):1655-1662

    A systematic review of the evidence for topical use of ginger

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    Background The use of ginger as a topical intervention is widely advocated in the popular media. However, there has been no attempt to date to synthesize the evidence for topically administered ginger. Objective To systematically review and synthesize the best available evidence of effectiveness for topical ginger in any condition. Data Sources CAM on PubMed, CINAHL, Google Scholar, MEDLINE, National Library of Australia, The Cochrane Library, TRIP, pertinent texts, and bibliographies of relevant papers. Study Selection Data sources were systematically searched for studies investigating the clinical effectiveness of topical ginger, in any form and for any condition, regardless of study design. Studies were limited to those published between 1980 and 2010, and published in English, Mandarin, Cantonese, or Taiwanese. Data Extraction Data were extracted by two authors, independently, using standardized templates. Data Synthesis Four studies met the inclusion criteria, including three randomized controlled trials and one non-randomized controlled trial. All studies differed in terms of study population, outcome measures, comparative interventions, and dose and form of ginger used, and thus, were not amenable to meta-analysis. Findings from all trials favored usage of ginger for most outcomes. However, the small sample sizes and inadequate methodological reporting indicate a high risk of bias and the need for caution when interpreting these results. Conclusions Few studies have investigated the effectiveness of topically administered ginger for any condition. Until the findings of these studies are corroborated by more robust research, and the safety of ginger is adequately established, clinicians should remain cautious about using topical ginger in clinical practice
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