Dynamic Morphometry Research Articles

Predicting Bone Adaptation in Astronauts during and after Spaceflight.

A method was previously developed to identify participant-specific parameters in a model of trabecular bone adaptation from longitudinal computed tomography (CT) imaging. In this study, we use these numerical methods to estimate changes in astronaut bone health during the distinct phases of spaceflight and recovery on Earth. Astronauts (N = 16) received high-resolution peripheral quantitative CT (HR-pQCT) scans of their distal tibia prior to launch (L), upon their return from an approximately six-month stay on the international space station (R+0), and after six (R+6) and 12 (R+12) months of recovery. To model trabecular bone adaptation, we determined participant-specific parameters at each time interval and estimated their bone structure at R+0, R+6, and R+12. To assess the fit of our model to this population, we compared static and dynamic bone morphometry as well as the Dice coefficient and symmetric distance at each measurement. In general, modeled and observed static morphometry were highly correlated (R2> 0.94) and statistically different (p < 0.0001) but with errors close to HR-pQCT precision limits. Dynamic morphometry, which captures rates of bone adaptation, was poorly estimated by our model (p < 0.0001). The Dice coefficient and symmetric distance indicated a reasonable local fit between observed and predicted bone volumes. This work applies a general and versatile computational framework to test bone adaptation models. Future work can explore and test increasingly sophisticated models (e.g., those including load or physiological factors) on a participant-specific basis.

Trabecular bone remodeling in the aging mouse: A micro-multiphysics agent-based in silico model using single-cell mechanomics.

Bone remodeling is regulated by the interaction between different cells and tissues across many spatial and temporal scales. Notably, in silico models are regarded as powerful tools to further understand the signaling pathways that regulate this intricate spatial cellular interplay. To this end, we have established a 3D multiscale micro-multiphysics agent-based (micro-MPA) in silico model of trabecular bone remodeling using longitudinal in vivo data from the sixth caudal vertebra (CV6) of PolgA(D257A/D257A) mice, a mouse model of premature aging. Our in silico model includes a variety of cells as single agents and receptor-ligand kinetics, mechanomics, diffusion and decay of cytokines which regulate the cells' behavior. We highlighted its capabilities by simulating trabecular bone remodeling in the CV6 of five mice over 4weeks and we evaluated the static and dynamic morphometry of the trabecular bone microarchitecture. Based on the progression of the average trabecular bone volume fraction (BV/TV), we identified a configuration of the model parameters to simulate homeostatic trabecular bone remodeling, here named basal. Crucially, we also produced anabolic, anti-anabolic, catabolic and anti-catabolic responses with an increase or decrease by one standard deviation in the levels of osteoprotegerin (OPG), receptor activator of nuclear factor kB ligand (RANKL), and sclerostin (Scl) produced by the osteocytes. Our results showed that changes in the levels of OPG and RANKL were positively and negatively correlated with the BV/TV values after 4weeks in comparison to basal levels, respectively. Conversely, changes in Scl levels produced small fluctuations in BV/TV in comparison to the basal state. From these results, Scl was deemed to be the main driver of equilibrium while RANKL and OPG were shown to be involved in changes in bone volume fraction with potential relevance for age-related bone features. Ultimately, this micro-MPA model provides valuable insights into how cells respond to their local mechanical environment and can help to identify critical pathways affected by degenerative conditions and ageing.

Pelvic floor muscle dysfunction at 3D transperineal ultrasound in maternal exposure to gestational diabetes mellitus: A prospective cohort study during pregnancy.

This study aimed to assess, for the first time, the dynamic morphometry of pelvic floor muscles (PFM) using three-dimensional transperineal ultrasound (3D-TPUS) and its progression at two-time points of gestation between women with and without gestational diabetes mellitus (GDM), and whether the PFM dysfunction is connected to GDM. The study comprised 83 consecutive pregnant women with (n = 38) and without (n = 45) GDM screened at 24-30 and 38-40 weeks of gestation. 3D-TPUS and a mobility test were used to quantify PFM dynamic morphometry during maximum contraction and the Valsalva maneuver. When compared to the control group, GDM women had no significant variations in all levator hiatal dimensions at 24-30 weeks of gestation. Meanwhile, women with GDM experienced an increase in levator hiatal area (LHa) (p < 0.000) during PFM contraction and enlargement in LHa (p < 0.001) during Valsalva maneuver (p = 0.010) at 38-40 weeks of gestation. As a result, the mobility index among GDM women had a lower value (p = 0.000). The dynamic morphometry development of PFM in GDM women at two stages during pregnancy revealed a substantial decrease (p = 0.000) in all LHadimensions of contraction, distension, and mobility. Using 3D-TPUS, we found that GDM women had a specific pattern of PFM functional changes in the third trimester of pregnancy. These initial findings revealed alterations in PFM functionality, such as decreased contractility, distensibility, or mobility. This dysfunctional PFM could contribute to the long-term development of pelvic floor dysfunction years after a GDM pregnancy.

Arch volume：a new method for medial longitudinal arch measurement

BackgroundAs a flexible and elastic structure, the dynamic morphometry of medial longitudinal arch remains to be an unresolved Issue for clinic. Here we introduce a new measurement named arch volume to describe the morphological changes of the medial longitudinal arch during weight-bearing and compare with present method for measuring MLA. Methods64 healthy participants were enrolled. And the dynamic arch morphology was measured under four weight bearing status with navicular height, arch area and arch volume, respectively. ResultsWith the increase of weight loading, the flattening or slightly deformation of medial longitudinal arch was observed by all method (p<0.05). However, as a 3D indicator, arch volume not only showed higher sensitivity than other method, but also provide visualization of MLA during loading changing. ConclusionsCompared with navicular height and arch area, arch volume has a significant advantage in describing arch morphological changes under different weight bearing status.

Ex vivo Evaluation of the Dynamic Morphometry of the Caudal Cervical Intervertebral Disc Spaces of Small Dogs and Cats.

The objective of this study was to provide a morphometric description of the caudal cervical intervertebral disc (IVD) spaces of small-breed dogs and cats. Specimens consisting of C4 through C7 from five small-breed dogs and six cats were positioned in neutral, flexion, extension, and lateral bending positions; and CT images were acquired. Height and width of the cranial and caudal vertebral endplates (VEPs), angle between the VEPs (IVD wedge angle), and craniocaudal distance (IVD width) between VEPs for the four loading positions were measured and compared for three segments (C4–C5, C5–C6, and C6–C7). VEP size normalized to body weight from medium-sized dogs was retrieved from a previous study and compared with data from small dogs and cats. A linear mixed model was used to compare outcome measures. Significance was set to p < 0.05. VEP size normalized to body weight was the largest in small dogs compared with cats (p = 0.0422) and medium-sized dogs (p = 0.0064). Cats and medium-sized dogs were similar (p = 0.2763) in this regard. Flexion and extension induced a reduction of IVD width in the ventral portion of the IVD and the area of the nucleus. The dorsal part of the IVD remained unchanged throughout loading conditions. Unique morphometric characteristics of the caudal cervical IVD space of small dogs and cats were detected that are different from those described in sizes of dogs (medium-sized) typically affected by caudal cervical spondylomyelopathy (CSM). These findings may help to understand the different pathomechanisms in cervical spinal disease between small- and medium-sized dogs, including caudal CSM.

Pelvic floor muscle dysfunction on 3D/4D transperineal ultrasound in patients with deep infiltrating endometriosis: a pilot study.

Pelvic floor muscle (PFM) dysfunction seems to play an important role in the pathophysiology of pelvic pain, including that associated with deep infiltrating endometriosis (DIE). The aim of this study was to evaluate the static and dynamic morphometry of the PFM using three-dimensional (3D) and four-dimensional (4D) transperineal ultrasound in women with DIE compared with asymptomatic healthy women. This was a pilot, prospective study conducted at our tertiary center between March and November 2015. Fifty nulliparous women with DIE (study group) and 35 nulliparous asymptomatic healthy women (control group) were included. 3D/4D transperineal ultrasound examination of the PFM was performed in both groups. Levator hiatal area (LHA) and anteroposterior and left-right transverse diameters were evaluated at rest, on maximum PFM contraction and on maximum Valsalva maneuver. Persistent levator ani muscle (LAM) coactivation during Valsalva maneuver was investigated. Compared with the control group, women with DIE had a smaller LHA at rest (P = 0.03) and during Valsalva maneuver (P < 0.01). Furthermore, reduction in LHA during PFM contraction (P < 0.001) and enlargement in LHA during Valsalva maneuver (P = 0.01) were significantly less marked. In comparison with controls, women with DIE presented a higher frequency of LAM coactivation during Valsalva maneuver, although this difference did not reach statistical significance (P = 0.05). 3D and 4D transperineal ultrasound is an objective and non-invasive method for PFM morphometry and may have a role in detecting PFM dysfunction in women with DIE. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

The Clinical Biomechanics Award 2012 — Presented by the European Society of Biomechanics: Large scale simulations of trabecular bone adaptation to loading and treatment

BackgroundMicrostructural simulations of bone remodeling are particularly relevant in the clinical management of osteoporosis. Before a model can be applied in the clinics, a validation against controlled in vivo data is crucial. Here we present a strain-adaptive feedback algorithm for the simulation of trabecular bone remodeling in response to loading and pharmaceutical treatment and report on the results of the large-scale validation against in vivo data. MethodsThe algorithm follows the mechanostat principle and incorporates mechanical feedback, based on the local strain-energy density. For the validation, simulations of bone remodeling and adaptation in 180 osteopenic mice were performed. Permutations of the conditions for early (20th week) and late (26th week) loading of 8N or 0N, and treatments with bisphosphonates, or parathyroid hormone were simulated. Static and dynamic morphometry and local remodeling sites from in vivo and in silico studies were compared. FindingsFor each study an individual set of model parameters was selected. Trabecular bone volume fraction was chosen as an indicator of the accuracy of the simulations. Overall errors for this parameter were 0.1–4.5%. Other morphometric indices were simulated with errors of less than 19%. Dynamic morphometry was more difficult to predict, which resulted in significant differences from the experimental data. InterpretationWe validated a new algorithm for the simulation of bone remodeling in trabecular bone. The results indicate that the simulations accurately reflect the effects of treatment and loading seen in respective experimental data, and, following adaptation to human data, could be transferred into clinics.

Recent Patents on Morphometric Analysis of Eukaryotic Cells

Eukaryotic cells are complex structures formed by several compartments. They present dynamic morphometry and functions, which are assessed in basic cell research to elucidate their behavior in response to different interventions, as well as to study several pathogenic processes and for diagnosis and therapy. Due to this wide use, new methods, tools and designs concerning the structural and functional imaging study of eukaryotic cells have been continuously developed, generating several patents that are deposited at the main offices of intellectual property around the world. Here, we reviewed the recent patents on morphometric analysis of eukaryotic cells deposited in the main patent databanks, i.e. the United States Patent and Trademark Office (USPTO), the European Patent Office (EPO) and the World Intellectual Property Organization (WIPO). We found fifty four patents covering several morphometric aspects of eukaryotic cells, such as general cell morphology, organelles and nuclear morphology, three-dimensional imaging and live cell imaging. Patents related to methods in tissue imaging were also included. We further classified each patent according to its use (i.e. in vitro or in vivo) and applicability (i.e. research, diagnosis or therapy). At the end, we discuss in an integrate manner the main aspects and significance of the reported patents. Keywords: Eukaryotic cell imaging, general cell morphology, live cell imaging, nuclear morphology, organelles morphology, three-dimensional imaging, tissue imaging.

Standardization of whole slide image morphologic assessment with definition of a new application: Digital slide dynamic morphometry

Background: In histopathology, the quantitative assessment of various morphologic features is based on methods originally conceived on specific areas observed through the microscope used. Failure to reproduce the same reference field of view using a different microscope will change the score assessed. Visualization of a digital slide on a screen through a dedicated viewer allows selection of the magnification. However, the field of view is rectangular, unlike the circular field of optical microscopy. In addition, the size of the selected area is not evident, and must be calculated. Materials and Methods: A digital slide morphometric system was conceived to reproduce the various methods published for assessing tumor budding in colorectal cancer. Eighteen international experts in colorectal cancer were invited to participate in a web-based study by assessing tumor budding with five different methods in 100 digital slides. Results: The specific areas to be tested by each method were marked by colored circles. The areas were grouped in a target-like pattern and then saved as an .xml file. When a digital slide was opened, the .xml file was imported in order to perform the measurements. Since the morphometric tool is composed of layers that can be freely moved on top of the digital slide, the technique was named digital slide dynamic morphometry. Twelve investigators completed the task, the majority of them performing the multiple evaluations of each of the cases in less than 12 minutes. Conclusions: Digital slide dynamic morphometry has various potential applications and might be a useful tool for the assessment of histologic parameters originally conceived for optical microscopy that need to be quantified.

Microradiography and fluorescence microscopy of bone remodeling on the basal crypt of permanent mandibular premolars in dogs during eruption.

Alveolar bone of erupting teeth was studied in order to define the types of calcified tissues deposited as well as the rate of tooth growth. The third (P3) and fourth (P4) mandibular premolars of 30 dogs aged 12-24 weeks were analyzed by microradiography and microscopy in fluorescent and ordinary light. The bone plate separating P3 and P4 from the mandibular canal presented a complex arrangement of lamellar and woven bone, and even of chondroid tissue. During the pre-eruptive phase, this plate shifted towards the base of the mandible by means of selective resorption and apposition activities. As soon as the furcation was formed, bone apposition appeared on the alveolar side and became the main activity under P3 at the outset of eruption. Under the roots of P4 it occurred 4 weeks later. Dynamic morphometry in fluorescence microscopy showed that eruption progressed faster than the radicular growth. The formation of interradicular bone underwent the same acceleration as the eruption. However, though the tissues were formed at a high rate, it cannot be inferred therefrom that they are responsible for tooth shifting. They might just fill the space left by the erupting tooth.

Three‐dimensional dynamic morphometry on a diffraction pattern in the focal plane

SUMMARYA new type of morphometry, which shortens the scanning time of precise observation by confocal microscopy, has been investigated.To analyse the 3‐D distribution of active sites on a living cell, microspheres of the same size were immunologically marked on specific sites on a cell. Incident coherent light was scattered on the microspheres and the scattered light from each microsphere superimposed upon each other giving a diffraction pattern of the examined cell. Several series of interference fringes were generated on the diffraction pattern, according to the phase difference of the microspheres. These interference fringes on the 2‐D diffraction pattern enable the (relative) 3‐D positions of the microspheres to be determined.3‐D dynamic morphometry on a 2‐D diffraction pattern with interference fringes speeds up imaging in confocal microscopy.