Citations

Abstract The frequent von Willebrand factor (VWF) variant p.Phe2561Tyr is located within the C4 domain, which also harbors the platelet GPIIb/IIIa-binding RGD sequence. To investigate its potential effect on hemostasis, we genotyped 865 patients with coronary artery disease (CAD), 915 with myocardial infarction (MI), and 417 control patients (Ludwigshafen Risk and Cardiovascular Health Study) and performed functional studies of this variant. A univariate analysis of male and female carriers of the Tyr2561 allele aged 55 years or younger revealed an elevated risk for repeated MI (odds ratio, 2.53; 95% confidence interval [CI], 1.07-5.98). The odds ratio was even higher in females aged 55 years or younger, at a value of 5.93 (95% CI, 1.12-31.24). Cone and plate aggregometry showed that compared with Phe2561, Tyr2561 was associated with increased platelet aggregate size both in probands’ blood and with the recombinant variants. Microfluidic assays revealed that the critical shear rate for inducing aggregate formation was decreased to 50% by Tyr2561 compared with Phe2561. Differences in C-domain circular dichroism spectra resulting from Tyr2561 suggest an increased shear sensitivity of VWF as a result of altered association of the C domains that disrupts the normal dimer interface. In summary, our data emphasize the functional effect of the VWF C4 domain for VWF-mediated platelet aggregation in a shear-dependent manner and provide the first evidence that a functional variant of VWF plays a role in arterial thromboembolism.

AbstractBackgroundThe study aims were to model acute pain intensity and opioid consumption trajectories up to 72 hr after open hepatic resection, identify predictors of trajectory membership and examine the association between trajectory memberships and 6‐month pain and psychological outcomes. This is a long‐term analysis of a published randomized controlled trial on the impact of medial open transversus abdominis plane catheters on post‐operative outcomes.MethodsA total of 152 patients (89 males; mean age 63.0 [range: 54–72]) completed questionnaires on pain and related characteristics pre‐operatively and 6 months post‐operatively. Total opioid use was recorded several times over a 72‐hr period while self‐reported pain intensity scores were collected multiple times until hospital discharge. Analyses were carried out using growth mixture modelling, logistic regression and general linear models.ResultsBoth pain intensity and opioid consumption showed that a four‐trajectory model best fits the data. Patients in the lowest opioid consumption trajectory were more likely to be classified in the constant mild pain intensity trajectory. Age and baseline levels of anxiety significantly predicted opioid trajectory membership while baseline depressive symptoms significantly predicted pain intensity trajectory membership. Patients in the two highest opioid consumption trajectories reported significantly higher levels of pain catastrophizing at 6 months compared to patients in the other 3 trajectories (all p < 0.05).ConclusionHigh consumption of opioids after surgery is associated with higher levels of pain catastrophizing 6 months later. Identification of patients within these trajectories may lead to the development of early interventions targeted to high risk individuals.SignificanceDifferences in initial levels of opioid consumption and rates of change in opioid consumption shortly after surgery can help predict long‐term psychological responses to pain. Identifying key characteristics associated with initial opioid consumption can lead to the development of cost‐effective early interventions targeted to high risk individuals.

Purpose To determine baseline individual and school-related factors associated with increased risk of developing depression symptoms by year four (Y4) of medical school, and to develop a prognostic index that stratifies risk of developing depression symptoms (Depression-PI) among medical students. Method The authors analyzed data from 3,743 students (79% of 4,732) attending 49 U.S. medical schools who completed baseline (2010) and Y4 (2014) surveys. Surveys included validated scales measuring depression, stress, coping, and social support. The authors collected demographics and school characteristics and conducted multivariate analysis to identify baseline factors independently associated with Y4 depression symptoms. They used these factors to create a prognostic index for developing depression. They randomly divided the data into discovery (n = 2,455) and replication (n = 1,288) datasets and calculated c statistics ( c ). Results The authors identified eight independent prognostic factors for experiencing depression symptoms during training within the discovery dataset: age; race; ethnicity; tuition; and baseline depression symptoms, stress, coping behaviors, and social support. The Depression-PI stratified four risk groups. Compared with the low risk group, those in the intermediate, high, and very high risk groups had an odds ratio of developing depression of, respectively, 1.75, 3.98, and 9.19 ( c = 0.71). The replication dataset confirmed the risk groups. Conclusions Demographics; tuition; and baseline depression symptoms, stress, coping behaviors, and social support are independently associated with risk of developing depression during training among U.S. medical students. By stratifying students into four risk groups, the Depression-PI may allow for a tiered primary prevention approach.