Cartilage loss patterns within femorotibial contact regions during deep knee bend

AbstractOsteoarthritis (OA) can alter knee kinematics and stresses. The relationship between cartilage loss in OA and kinematics is unclear, with existing work focusing on static wear and morphology. In this work, femorotibial cartilage maps were coupled with kinematics to investigate the relationship between kinematics and cartilage loss, allowing for more precise treatment and intervention. Cartilage thickness maps were created from healthy and OA subgroups (varus, valgus, and neutral) and mapped to a statistical bone atlas. Video fluoroscopy determined contact regions from 0° to 120° flexion. Varus and valgus subgroups displayed different wear patterns across the range of flexion, with varus knees showing more loss in early flexion and valgus in deeper flexion. For the femur, varus knees had more wear in the medial compartment than neutral or valgus and most wear at both 0° and 20° flexion. In the lateral femoral compartment, the valgus subgroup showed significantly more wear from 20° to 60° flexion as compared to other angles, though varus knees displayed highest magnitude of wear. For the tibia, most medial wear occurred at 0–40° flexion and most lateral occurred after 60° flexion. Knowing more about cartilage changes in OA knees provides insight as to expected wear or stresses on implanted components after arthroplasty. Combining cartilage loss patterns with kinematics allows for pre-surgical intervention and treatments tailored to the patient׳s alignment and kinematics. Reported wear patterns may also serve as a gauge for post-operative loading to be considered when placing implant components

Fundamentals of bladder tissue engineering

A wide range of injuries could affect the bladder and lead to eventual loss of its integrity, with the need for replacement or repair. Augmentation ileocystoplasty is considered till now the gold standard option for bladder replacement, despite its associated complications. Bladder tissue engineering appears as an appealing alternative through development of biological substitutes, which could restore structural and functional aspects of damaged tissues and organs. Tissue engineering relies upon three essential pillars; the scaffold, the cells seeded on scaffolds and lastly the environmental conditions, including growth factors, cytokines and extracellular matrix (ECM) which promote angiogenesis and neurogenesis of the regenerated organs. The choice of the scaffold and the type of cells is a crucial and fundamental step in regenerative medicine. In this review article, we demonstrated these three crucial factors of bladder tissue engineering, with the pros and cons of each scaffold type and cell type used.Keywords: Scaffold; Stem cells; Bladder tissue engineering; Decellularization; Bladder acellular matrixAfrican Journal of Urology (2013) 19, 51–5

Present-day correlations are insufficient to predict cloud albedo change by anthropogenic aerosols in E3SM v2

Cloud albedo susceptibility to droplet number perturbation remains a source of uncertainty in understanding aerosol–cloud interactions and thus both past and present climate states. Through the Energy Exascale Earth System Model (E3SM) v2 experiments, we probe the effects of competing processes on cloud albedo susceptibility of low-lying marine stratocumulus in the northeast Pacific. In present-day conditions, we find that increasing precipitation suppression by aerosols increases cloud albedo susceptibility, whereas increasing cloud sedimentation decreases it. By constructing a hypothetical model configuration exhibiting negative susceptibility under all conditions, we conclude that cloud albedo change due to aerosol perturbation cannot be predicted by present-day co-variabilities in E3SM v2. As such, our null result herein challenges the assumption that present-day climate observations are sufficient to constrain past states, at least in the context of cloud albedo changes to aerosol perturbation.</p

Overlay virtualized wireless sensor networks for application in industrial internet of things : a review

Abstract: In recent times, Wireless Sensor Networks (WSNs) are broadly applied in the Industrial Internet of Things (IIoT) in order to enhance the productivity and efficiency of existing and prospective manufacturing industries. In particular, an area of interest that concerns the use of WSNs in IIoT is the concept of sensor network virtualization and overlay networks. Both network virtualization and overlay networks are considered contemporary because they provide the capacity to create services and applications at the edge of existing virtual networks without changing the underlying infrastructure. This capability makes both network virtualization and overlay network services highly beneficial, particularly for the dynamic needs of IIoT based applications such as in smart industry applications, smart city, and smart home applications. Consequently, the study of both WSN virtualization and overlay networks has become highly patronized in the literature, leading to the growth and maturity of the research area. In line with this growth, this paper provides a review of the development made thus far concerning virtualized sensor networks, with emphasis on the application of overlay networks in IIoT. Principally, the process of virtualization in WSN is discussed along with its importance in IIoT applications. Different challenges in WSN are also presented along with possible solutions given by the use of virtualized WSNs. Further details are also presented concerning the use of overlay networks as the next step to supporting virtualization in shared sensor networks. Our discussion closes with an exposition of the existing challenges in the use of virtualized WSN for IIoT applications. In general, because overlay networks will be contributory to the future development and advancement of smart industrial and smart city applications, this review may be considered by researchers as a reference point for those particularly interested in the study of this growing field

Co-registration of Sequential Multidetector Computed Tomography Studies for the Evaluation of Surgical Instrumentation following Resection of Spinal Tumors

Surgical resection of spinal tumors involves complex reconstructive procedures. The stability and integrity of the surgical construct are evaluated with multidetector computed tomography (MDCT). As coregistration, or fusion, of different imaging modalities, especially positron emission tomography/computed tomography (PET/CT), is common practice, we sought to determine if this technique could be applied to sequential, postoperative MDCT studies of the spine. Herein, we demonstrate that by utilizing the Hermes workstation, co-registration of MDCT spine studies can be performed. This technique allows sequential MDCT examinations of the post-operative spine to be viewed together as one study and may aid in evaluation of the position and integrity of the surgical construct over time. Further study and refinement of this technique will be necessary before clinical implementation

Clinical and statistical correlation of various lumbar pathological conditions

AbstractCurrent clinical evaluations often rely on static anatomic imaging modalities for diagnosis of mechanical low back pain, which provide anatomic snapshots and a surrogate analysis of a functional disease. Three dimensional in vivo motion is available with the use of digital fluoroscopy, which was used to capture kinematic data of the lumbar spine in order to identify coefficients of motion that may assist the physician in differentiating patient pathology. Forty patients distributed among 4 classes of lumbar degeneration, from healthy to degenerative, underwent CT, MRI, and digital x-ray fluoroscopy. Each patient underwent diagnosis by a neurosurgeon. Fluoroscopy was taken as the patient performed lateral bending (LB), axial rotation (AR) and flexion-extension (FE). Patient specific models were registered with the fluoroscopy images to obtain in vivo kinematic data. Motion coefficients, CLB, CAR, CFE, were calculated as the ratio of in-plane motion to total out-of-plane motion. Range of motion (ROM) was calculated about the axis of motion for each exercise. Inter- and Intra- group statistics were examined for each coefficient and a flexible Bayesian classifier was used to differentiate patients with degeneration. The motion coefficients CLB and CFE were significantly different (p<0.05) in 4 of 6 group comparisons. In plane motion, ROMLB, was significantly different in only 1 of 6 group comparisons. The classifier achieved 95% sensitivity and specificity using (CFE, CLB, ROMLB) as input features, and 40% specificity and 80% sensitivity using ROM variables. The new coefficients were better correlated with patient pathology than ROM measures. The coefficients suggest a relationship between pathology and measured motion which has not been reported previously

Inverse Association between trans Isomeric and Long-Chain Polyunsaturated Fatty Acids in Pregnant Women and Their Newborns: Data from Three European Countries

Background: trans unsaturated fatty acids are thought to interfere with essential fatty acid metabolism. To extend our knowledge of this phenomenon, we investigated the relationship between trans isomeric and long-chain polyunsaturated fatty acids (LCPUFA) in mothers during pregnancy and in their infants at birth. Methods: Fatty acid composition of erythrocyte phosphatidylcholine (PC) and phosphatidylethanolamine (PE) was determined in Spanish (n = 120), German (n = 78) and Hungarian (n = 43) women at the 20th and 30th week of gestation, at delivery and in their newborns. Results: At the 20th week of gestation, the sum of trans fatty acids in PE was significantly (p < 0.01) lower in Hungarian [0.73 (0.51), % wt/wt, median (IQR)] than in Spanish [1.42 (1.36)] and German [1.30 (1.21)] women. Docosahexaenoic acid (DHA) values in PE were significantly (p < 0.01) higher in Hungarian {[}5.65 (2.09)] than in Spanish [4.37 (2.60)] or German [4.39 (3.3.2)] women. The sum of trans fatty acids significantly inversely correlated to DHA in PCs in Spanish (r = -0.37, p < 0.001), German (n = -0.77, p < 0.001) and Hungarian (r = -0.35, p < 0.05) women, and in PEs in Spanish (r = -0.67, p < 0.001) and German (r = -0.71, p < 0.001), but not in Hungarian (r = -0.02) women. Significant inverse correlations were seen between trans fatty acids and DHA in PEs at the 30th week of gestation (n = 241, r = -0.52, p < 0.001), at delivery (n = 241, r = -0.40, p < 0.001) and in cord lipids (n = 218, r = -0.28, p < 0.001). Conclusion: Because humans cannot synthesize trans isomeric fatty acids, the data obtained in the present study support the concept that high maternal trans isomeric fatty acid intake may interfere with the availability of LCPUFA both for the mother and the fetus. Copyright (C) 2011 S. Karger AG, Base

Loneliness among women with rheumatoid arthritis:A cross-cultural study in the Netherlands and Egypt

The objective of this study was to explain loneliness as experienced by women with rheumatoid arthritis (RA) in a cross-cultural context. We studied 36 Egyptian female RA patients and 140 female Dutch RA patients.. Self-report data were collected about loneliness, physical and psychological health status, social support and social network, needs for help, attitudes and feelings of guilt. Loneliness was significantly higher among Egyptian (44.2 ± 32.3) than Dutch (12.9 ± 18.9) female RA patients (F = 54.3, p < 0.001). In Egypt, 36% of the variance of loneliness could be explained by worse affect (anxiety and depression; β = 0.51), fewer children (β = 0.31), and higher negative social support for the patients (β = 0.28) in multiple regression analysis. In the Netherlands, 35% of feeling lonely could be explained by worse affect scores (β = 0.52), less positive social support for the patients (β = 0.24), and a higher degree of disability (β = 0.21). Age of the patients and disease duration only explained 4% and 3% of the loneliness of RA patients in Egypt and the Netherlands, respectively. Female Egyptian RA patients experienced more loneliness than Dutch patients. Affect is the most important and constant variable in explaining loneliness in both countries. The role of the family in perceived loneliness is greater in Egypt than the Netherlands. Low social support received by patients is important in explaining loneliness in the Netherlands but not in Egypt

Transcriptomic signatures associated with regional cortical thickness changes in Parkinson's disease

Cortical atrophy is a common manifestation in Parkinson's disease (PD), particularly in advanced stages of the disease. To elucidate the molecular underpinnings of cortical thickness changes in PD, we performed an integrated analysis of brain-wide healthy transcriptomic data from the Allen Human Brain Atlas and patterns of cortical thickness based on T1-weighted anatomical MRI data of 149 PD patients and 369 controls. For this purpose, we used partial least squares regression to identify gene expression patterns correlated with cortical thickness changes. In addition, we identified gene expression patterns underlying the relationship between cortical thickness and clinical domains of PD. Our results show that genes whose expression in the healthy brain is associated with cortical thickness changes in PD are enriched in biological pathways related to sumoylation, regulation of mitotic cell cycle, mitochondrial translation, DNA damage responses, and ER-Golgi traffic. The associated pathways were highly related to each other and all belong to cellular maintenance mechanisms. The expression of genes within most pathways was negatively correlated with cortical thickness changes, showing higher expression in regions associated with decreased cortical thickness (atrophy). On the other hand, sumoylation pathways were positively correlated with cortical thickness changes, showing higher expression in regions with increased cortical thickness (hypertrophy). Our findings suggest that alterations in the balanced interplay of these mechanisms play a role in changes of cortical thickness in PD and possibly influence motor and cognitive functions.Neuro Imaging Researc