32 research outputs found

    Hierarchical Data-Driven Analysis of Clinical Symptoms Among Patients With Parkinson's Disease

    Get PDF
    Mutations in the LRRK2 and GBA genes are the most common inherited causes of Parkinson's disease (PD). Studies exploring phenotypic differences based on genetic status used hypothesis-driven data-gathering and statistical-analyses focusing on specific symptoms, which may influence the validity of the results. We aimed to explore phenotypic expression in idiopathic PD (iPD) patients, G2019S-LRRK2-PD, and GBA-PD using a data-driven approach, allowing screening of large numbers of features while controlling selection bias. Data was collected from 1525 Ashkenazi Jews diagnosed with PD from the Tel-Aviv Medical center; 161 G2019S-LRRK2-PD, 222 GBA-PD, and 1142 iPD (no G2019S-LRRK2 or any of the 7 AJ GBA mutations tested). Data included 771 measures: demographics, cognitive, physical and neurological functions, performance-based measures, and non-motor symptoms. The association of the genotypes with each of the measures was tested while accounting for age at motor symptoms onset, gender, and disease duration; p-values were reported and corrected in a hierarchical approach for an average over the selected measures false discovery rate control, resulting in 32 measures. GBA-PD presented with more severe symptoms expression while LRRK2-PD had more benign symptoms compared to iPD. GBA-PD presented greater cognitive and autonomic involvement, more frequent hyposmia and REM sleep behavior symptoms while these were less frequent among LRRK2-PD compared to iPD. Using a data-driven analytical approach strengthens earlier studies and extends them to portray a possible unique disease phenotype based on genotype among AJ PD. Such findings could help direct a more personalized therapeutic approach

    Isometric Scaling in Developing Long Bones Is Achieved by an Optimal Epiphyseal Growth Balance.

    No full text
    One of the major challenges that developing organs face is scaling, that is, the adjustment of physical proportions during the massive increase in size. Although organ scaling is fundamental for development and function, little is known about the mechanisms that regulate it. Bone superstructures are projections that typically serve for tendon and ligament insertion or articulation and, therefore, their position along the bone is crucial for musculoskeletal functionality. As bones are rigid structures that elongate only from their ends, it is unclear how superstructure positions are regulated during growth to end up in the right locations. Here, we document the process of longitudinal scaling in developing mouse long bones and uncover the mechanism that regulates it. To that end, we performed a computational analysis of hundreds of three-dimensional micro-CT images, using a newly developed method for recovering the morphogenetic sequence of developing bones. Strikingly, analysis revealed that the relative position of all superstructures along the bone is highly preserved during more than a 5-fold increase in length, indicating isometric scaling. It has been suggested that during development, bone superstructures are continuously reconstructed and relocated along the shaft, a process known as drift. Surprisingly, our results showed that most superstructures did not drift at all. Instead, we identified a novel mechanism for bone scaling, whereby each bone exhibits a specific and unique balance between proximal and distal growth rates, which accurately maintains the relative position of its superstructures. Moreover, we show mathematically that this mechanism minimizes the cumulative drift of all superstructures, thereby optimizing the scaling process. Our study reveals a general mechanism for the scaling of developing bones. More broadly, these findings suggest an evolutionary mechanism that facilitates variability in bone morphology by controlling the activity of individual epiphyseal plates

    Growth balance is optimized for minimum element drifting activity.

    No full text
    <p>Graphs showing the range of relative positions of the FP in which the total drifting activity of symmetry-breaking elements is minimal and the actual relative position of the FP in each bone as a function of total bone length. On the right of each graph is a 3D representation of an adult bone with colored marks of element locations. Throughout the development of all bones, the FP either overlaps or is in high proximity to the range of values that leads to minimal element drifting activity. Data for this figure are provided in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1002212#pbio.1002212.s004" target="_blank">S4 Data</a>.</p

    Growth balance remains invariant when stationary elements are present.

    No full text
    <p>Graphs showing growth at the proximal and distal ends of each bone as a function of the total length of the bone. Black vertical tags mark the ends of fitted lines, indicating time points at which an element either becomes stationary or begins to drift (the stationary elements are indicated by gray thick background in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1002212#pbio.1002212.g006" target="_blank">Fig 6</a>). Regression analysis shows that at all intervals during which a stationary element is detected, the proximal/distal growth rate balance remains invariable (0.87 ≤ <i>R</i><sup><i>2</i></sup> ≤ 0.99, <i>p</i>-value < 10e-05). Data for this figure are provided in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1002212#pbio.1002212.s003" target="_blank">S3 Data</a>.</p

    Isometric scaling is achieved by synchronization between element drifting patterns and growth balance.

    No full text
    <p>Graphs showing the physical positions of all elements residing between the growth plates and of the fixed plane in each bone as a function of total bone length. Stationary elements are highlighted with thick gray background and the physical position of the FP is marked by a blue line. On the right of each graph is a 3D representation of an adult bone with colored marks of element locations. As predicted by our model, elements located in high proximity to the FP remain stationary. Conversely, elements located distantly from the FP drift away from the FP, as the longer the distance, the farther the drift will be. Data for this figure are provided in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1002212#pbio.1002212.s004" target="_blank">S4 Data</a>.</p

    The fixed plane model for isometric scaling of long bones.

    No full text
    <p>Illustration of fixed planes formed at the transverse plane where the ratio between the distances from the distal and the proximal ends of the bone is equal to the ratio between the distal and the proximal growth rates. <b>(A)</b> When growth is symmetric, the relative position of an element located at 50% length (rectangle) is maintained, whereas an element located at 75% length (triangle) drifts proximally to maintain its relative position. <b>(B)</b> When distal growth rate is three times higher than proximal growth rate, the location of the FP is at the 75% length. As a result, the relative position of the triangle element is maintained, whereas the rectangle element drifts distally to maintain its relative position.</p
    corecore