Machine learning-based prediction of relapse in rheumatoid arthritis patients using data on ultrasound examination and blood test

Recent effective therapies enable most rheumatoid arthritis (RA) patients to achieve remission; however, some patients experience relapse. We aimed to predict relapse in RA patients through machine learning (ML) using data on ultrasound (US) examination and blood test. Overall, 210 patients with RA in remission at baseline were dichotomized into remission (n = 150) and relapse (n = 60) based on the disease activity at 2-year follow-up. Three ML classifiers [Logistic Regression, Random Forest, and extreme gradient boosting (XGBoost)] and data on 73 features (14 US examination data, 54 blood test data, and five data on patient information) at baseline were used for predicting relapse. The best performance was obtained using the XGBoost classifier (area under the receiver operator characteristic curve (AUC) = 0.747), compared with Random Forest and Logistic Regression (AUC = 0.719 and 0.701, respectively). In the XGBoost classifier prediction, ten important features, including wrist/metatarsophalangeal superb microvascular imaging scores, were selected using the recursive feature elimination method. The performance was superior to that predicted by researcher-selected features, which are conventional prognostic markers. These results suggest that ML can provide an accurate prediction of relapse in RA patients, and the use of predictive algorithms may facilitate personalized treatment options

Single Nucleotide Polymorphism WRN Leu1074Phe Is Associated with Prostate Cancer Susceptibility in Chinese Subjects

Deficiencies in the human DNA repair gene WRN are the cause of Werner syndrome, a rare autosomal recessive disorder characterized by premature aging and a predisposition to cancer. This study evaluated the association of WRN Leu1074Phe (rs1801195), a common missense single nucleotide polymorphism in WRN, with prostate cancer susceptibility in Chinese subjects. One hundred and forty-seven prostate cancer patients and 111 male cancer-free control subjects from 3 university hospitals in China were included. Blood samples were obtained from each subject, and the single nucleotide polymorphism WRN Leu1074Phe was genotyped by using a Snapshot assay. The results showed that WRN Leu1074Phe was associated with the risk of prostate cancer in Chinese men and that the TG/GG genotype displayed a decreased prevalence of prostate cancer compared with the TT genotype (OR＝0.58, 95%CI:0.35-0.97, p＝0.039). Through stratified analysis, more significant associations were revealed for the TG/GG genotype in the subgroup with diagnosis age <_ 72 yr (OR＝0.27, 95%CI:0.12-0.61, p＝0.002) and in patients with localized diseases (OR＝0.36, 95%CI:0.19-0.70, p＝0.003). However, no statistically significant difference was found in the subgroup with age ＞72 yr or in patients with advanced diseases. We concluded that the genetic variant Leu1074Phe in the DNA repair gene WRN might play a role in the risk of prostate cancer in Chinese subjects

Correlation between Reynolds number and stenosis morphology in eccentric and concentric artery models

Atherosclerotic plaques within coronary arteries result in coronary stenosis which compromises blood flow to the distal myocardium and result in local physiological perturbances such as recirculation and shear stress. Coronary lesion severity is often graded by the amount of lumen encroachment or stenosis it causes, and most clinical decisions are made based on lesion stenosis severity. However, other lesion characteristics, such as eccentricity are determinants of both shear rate and the extent of flow recirculation in in-vitro and in computational fluid dynamics (CFD) analysis of the arteries. It has been shown that 81% of the coronary lesions studied by intravascular sonography were eccentric and the eccentric lesions are more likely to be seen in patients with cardiovascular symptoms. In this study, a particle image velocimetry (PIV) method was used to analyse the effect of the eccentricity on blood flow dynamics during a transient flow cycle and also to investigate how the eccentricity impact on the flow behaviour changes as the Reynolds number changes. Two eccentric and concentric stenosis models were manufactured from silicone (R'Tech Co., Ltd, Japan). All models were a box-type with an inner diameter of 4 mm (Fig. 1). The model sizes were based on the values of the human left main artery (LMA) and left anterior descending (LAD). The resultant models had a 70% diameter stenosis based on NASCET (North American Symptomatic Endarterectomy). The models were connected to a particle image velocimetry (PIV) circuit and an Nd:YAG solid laser (BWN-532-100E, B&W TEK Inc., USA) of wavelength 532 nm and output power 100 mW was used to produce a light sheet of 1 mm thickness in the desired area of visualization. The desired thickness and width of the light sheet were achieved by aligning a micro lens with 105 mm focal length and 2.8 F ratio (Micro-Nikkor, Nikon Co. Ltd., Japan). A pulsatile flow waveform was generated using a screw pump (NBL30PU, R’Tech Co. Ltd., Japan). At different times corresponding to different Reynolds numbers (Re = DU/v, D is the diameter of the parent artery, U is the velocity at the centre of the parent artery and v is the kinematic viscosity), the maximum axial velocity, shear strain rate and the recirculation length were measured for both eccentric and concentric models and compared with each other.11 page(s

Flow observations in elastic stenosis biomodel with comparison to rigid-like model

Background: Plaques in blood vessels exhibit a wide range of stiffness depending on disease conditions: stiffness is an important factor in plaque behavior. The geometrical change in plaque based on its behavior can affect blood flow patterns. Thus, it is important to study both blood flow and deformation of plaques and blood vessels. Objective: This study aims to identify the differences in flow conditions between in vitro models to discuss experimental materials for arterial wall and flow observation. Methods: In order to observe the blood flow pattern and plaque deformation simultaneously, a PVA-H stenosis model was used. In addition, a silicone model was also used as a rigid-like model for comparison with the PVA-H model. PIV was employed to measure the flow velocity distribution and determine the flow levels in the models. Results: PVA-H model exhibits expansion with an increase in upstream pressure and silicone model maintains the diameter. The expansion depends on their mechanical properties and influences flow conditions such as velocity changes and RAP in the parent artery. The balance between the expansion and change in flow conditions determines the final geometries of PVA-H model and flow pattern. Conclusions: The results suggest that the stiffness measurement for blood vessels and plaques such as ultrasound measurements would be important for accurate treatments.10 page(s

Correlation between Reynolds number and eccentricity effect in stenosed artery models

Background: Flow recirculation and shear strain are physiological processes within coronary arteries which are associated with pathogenic biological pathways. Distinct Quite apart from coronary stenosis severity, lesion eccentricity can cause flow recirculation and affect shear strain levels within human coronary arteries. Objective: The aim of this study is to analyse the effect of lesion eccentricity on the transient flow behaviour in a model of a coronary artery and also to investigate the correlation between Reynolds number (Re) and the eccentricity effect on flow behaviour. Methods: A transient particle image velocimetry (PIV) experiment was implemented in two silicone based models with 70% diameter stenosis, one with eccentric stenosis and one with concentric stenosis. Results: At different times throughout the flow cycle, the eccentric model was always associated with a greater recirculation zone length, maximum shear strain rate and maximum axial velocity; however, the highest and lowest impacts of eccentricity were on the recirculation zone length and maximum shear strain rate, respectively. Analysis of the results revealed a negative correlation between the Reynolds number (Re) and the eccentricity effect on maximum axial velocity, maximum shear strain rate and recirculation zone length. Conclusions: As Re number increases the eccentricity effect on the flow behavior becomes negligible.11 page(s

Comparison of flow patterns around stenotic area in elastic PVA-H model and in rigid-like silicone model

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Efficacy and Safety of Transurethral Enucleation with Bipolar Energy for Treatment of Benign Prostatic Hyperplasia: Does Prostate Volume Matter?

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Viscosity measurement of Xanthan–Poly(vinyl alcohol) mixture and its effect on the mechanical properties of the hydrogel for 3D modeling

Abstract Biomodels made of poly(vinyl alcohol) (PVA) are demanded because they can represent the geometries and mechanical properties of human tissues realistically. Injecting and molding, commonly used in three-dimensional (3D) modeling, help to represent the blood vessels accurately. However, these techniques sometimes require higher pressures than the upper pressure limit of the dispensers for pouring in high viscosity materials; the material viscosity should therefore be lower. Moreover, the mechanical properties of the biomodels should be reproduced. This study proposes a PVA solution through the addition of xanthan gum (XG) for 3D modeling, which lowers liquid viscosity while maintaining the mechanical properties of biomodels. XG is known to facilitate the achievement of non-Newtonian fluidity; however, the effects of XG on a PVA solution and PVA hydrogel (PVA-H) are not confirmed. The viscosity measurement using 15 wt% PVA with XG solution (PVA/XG) shows that it will provide easier pouring than 17 wt% PVA solution. The tensile test using the PVA-H of PVA(15 wt%)/XG(0.2 wt%) reveals that the gel is comparable in Young’s modulus to 17 wt% PVA-H. X-ray diffraction shows the crystalline structures of the PVA/XG gel and PVA-H are identical. Thus, this PVA/XG would be useful for fabricating biomodels using injection molding techniques