Prediction of second neurological attack in patients with clinically isolated syndrome using support vector machines

The aim of this study is to predict the conversion from clinically isolated syndrome to clinically definite multiple sclerosis using support vector machines. The two groups of converters and non-converters are classified using features that were calculated from baseline data of 73 patients. The data consists of standard magnetic resonance images, binary lesion masks, and clinical and demographic information. 15 features were calculated and all combinations of them were iteratively tested for their predictive capacity using polynomial kernels and radial basis functions with leave-one-out cross-validation. The accuracy of this prediction is up to 86.4% with a sensitivity and specificity in the same range indicating that this is a feasible approach for the prediction of a second clinical attack in patients with clinically isolated syndromes, and that the chosen features are appropriate. The two features gender and location of onset lesions have been used in all feature combinations leading to a high accuracy suggesting that they are highly predictive. However, it is necessary to add supporting features to maximise the accuracy. © 2013 IEEE

Using a pathway dynamics approach to characterise the role of ions, accessory proteins and ligands on G protein-coupled receptor signalling.

Accessory proteins and ions are able to modulate the signalling mechanisms of certain GPCRs, and it’s been established that accessory proteins are necessary for processes such as receptor trafficking to the membrane, ligand binding, activation and deactivation of a GPCR. More notably, a disruption that impacts the role of an accessory protein can result in disease states. To advance drug discovery & development that targets GPCRs, it is crucial the role of accessory proteins is characterised. This will assist the development of improved therapeutics with better selectivity, reduced off-target effects and an enhancement in the desired phenotypes when targeting the MC4R and EP4R for metabolic and cardiovascular diseases, respectively. In this thesis, the role of calcium and the accessory protein, MRAP2, has been characterised in the MC4R signalling. Furthermore, a small library of EP4R agonists was screened and compound CAY10580 was identified to have distinctive molecular signalling features, which exhibited physiological changes which may be beneficial in treating cardiac fibrosis. In addition, for the first time, the role of the accessory protein, EPRAP, in EP4R signalling has been explored using real-time assays which illustrated the importance of EPRAP in b-arrestin recruitment. The results obtained as part of the work conducted in this thesis unveils the importance of ions and accessory proteins in GPCR signalling. These findings expand upon the previous molecular mechanism profiles of the MC4R and EP4R along with novel findings, which in turn aids the development of improved therapeutics

Structure reveals the activation mechanism of the MC4 receptor to initiate satiation signaling

Obesity is a global epidemic causing morbidity and impaired quality of life. The melanocortin receptor 4 (MC4R) is at the crux of appetite, energy homeostasis, and body-weight control in the central nervous system and is a prime target for anti-obesity drugs. Here, we present the cryo-EM structure of the human MC4R-Gs signaling complex bound to the agonist setmelanotide, a cyclic peptide recently approved for the treatment of obesity. The work reveals the mechanism of MC4R activation, highlighting a molecular switch that initiates satiation signaling. In addition, our findings indicate that Ca2+ is required for agonist but not antagonist efficacy. These results fill a gap in understanding MC4R activation and could guide the design of future weight management drugs

Do children with central venous line (CVL) dysfunction have increased risk of symptomatic thromboembolism compared to those without CVL-dysfunction, while on cancer therapy?

<p>Abstract</p> <p>Background</p> <p>Thromboembolism (TE) and infection are two common complications of central venous line (CVL). Thrombotic CVL-dysfunction is a common, yet less studied, complication of CVL. Two retrospective studies have reported significant association of CVL-dysfunction and TE. Recent studies indicate association of CVL-related small clot with infection. Infection is the most common cause of non-cancer related mortality in children with cancer. We and others have shown reduced overall survival (OS) in children with cancer and CVL-dysfunction compared to those without CVL-dysfunction. Despite these observations, to date there are no prospective studies to evaluate the clinical significance of CVL-dysfunction and it’s impact on the development of TE, infection, or outcome of children with cancer.</p> <p>Study design</p> <p>This is a prospective, analytical cohort study conducted at five tertiary care pediatric oncology centers in Ontario. Children (≤ 18 years of age) with non-central nervous system cancers and CVL will be eligible for the study. Primary outcome measure is symptomatic TE and secondary outcomes are infection, recurrence of cancer and death due to any cause. Data will be analyzed using regression analyses.</p> <p>Discussion</p> <p>The overall objective is to delineate the relationship between CVL-dysfunction, infection and TE. The primary aim is to evaluate the role of CVL-dysfunction as a predictor of symptomatic TE in children with cancer. We hypothesize that children with CVL-dysfunction have activation of the coagulation system resulting in an increased risk of symptomatic TE. The secondary aims are to study the impact of CVL-dysfunction on the rate of infection and the survival [OS and event free survival (EFS)] of children with cancer. We postulate that patients with CVL-dysfunction have an occult CVL-related clot which acts as a microbial focus with resultant increased risk of infection. Further, CVL-dysfunction by itself or in combination with associated complications may cause therapy delays resulting in adverse outcome.</p> <p>This study will help to identify children at high risk for TE and infection. Based on the study results, we will design randomized controlled trials of prophylactic anticoagulant therapy to reduce the incidence of TE and infection. This in turn will help to improve the outcome in children with cancer.</p

Efficacy and safety of once weekly subcutaneous idrabiotaparinux in the treatment of patients with symptomatic deep venous thrombosis.

BACKGROUND: Idraparinux, a long acting inhibitor of factor (F) Xa, is as effective as standard anticoagulant therapy for patients with symptomatic deep venous thrombosis. We investigated the potential use of the biotinylated molecule, idrabiotaparinux. Biotinylation enables reversal of the anticoagulant effect. METHODS: We performed a randomized double-blind trial in 757 patients with symptomatic deep venous thrombosis, comparing equimolar doses of idrabiotaparinux (3 mg) with idraparinux (2.5 mg), both given subcutaneously, once weekly for 6 months. Inhibition of FXa activity was measured at days 15, 36, 57, 92 and 183. The efficacy outcome was recurrent venous thromboembolism. The safety outcomes were clinically relevant bleeding and death. RESULTS: Inhibition of FXa was similar in the two treatment groups at each time point of measurement. Recurrent venous thromboembolism during the 6-month treatment period occurred in nine of 386 patients (2.3%) in the idrabiotaparinux group and in 12 of 371 patients (3.2%) in the idraparinux group, a difference of - 0.9% (95% confidence interval, -3.2-1.4%). The incidence of clinically relevant bleeding was 5.2% in the idrabiotaparinux group and 7.3% in the idraparinux group (P = 0.29), a difference of - 2.1% (95% confidence interval, -5.6-1.4%). Six patients (1.6%) who received idrabiotaparinux died, compared with 12 patients (3.2%) given idraparinux, a difference of - 1.7% (95% confidence interval, -3.9-0.5%). CONCLUSIONS: Idrabiotaparinux has a similar time course of FXa inhibition, efficacy and safety to idraparinux for the treatment of deep venous thrombosis