Dynamics of the Tracheal Airway and Its Influences on Respiratory Airflows: An Exemplar Study

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Bora Sul ◽  
Talissa Altes ◽  
Kai Ruppert ◽  
Kun Qing ◽  
Daniel S. Hariprasad ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Minute Ventilation ◽  
Correlation Coefficients ◽  
Dynamic Imaging ◽  
Imaging Data ◽  
Cross Sectional ◽  
Mild Conditions ◽  
Large Airways ◽  
Magnetic Resonance Imaging Mri

Respiration is a dynamic process accompanied by morphological changes in the airways. Although deformation of large airways is expected to exacerbate pulmonary disease symptoms by obstructing airflow during increased minute ventilation, its quantitative effects on airflow characteristics remain unclear. Here, we used in vivo dynamic imaging and examined the effects of tracheal deformation on airflow characteristics under different conditions based on imaging data from a single healthy volunteer. First, we measured tracheal deformation profiles of a healthy lung using magnetic resonance imaging (MRI) during forced exhalation, which we simulated to characterize the subject-specific airflow patterns. Subsequently, for both inhalation and exhalation, we compared the airflows when the modeled deformation in tracheal cross-sectional area was 0% (rigid), 33% (mild), 50% (moderate), or 75% (severe). We quantified differences in airflow patterns between deformable and rigid airways by computing the correlation coefficients (R) and the root-mean-square of differences (Drms) between their velocity contours. For both inhalation and exhalation, airflow patterns were similar in all branches between the rigid and mild conditions (R > 0.9; Drms < 32%). However, airflow characteristics in the moderate and severe conditions differed markedly from those in the rigid and mild conditions in all lung branches, particularly for inhalation (moderate: R > 0.1, Drms < 76%; severe: R > 0.2, Drms < 96%). Our exemplar study supports the use of a rigid airway assumption to compute flows for mild deformation. For moderate or severe deformation, however, dynamic contraction should be considered, especially during inhalation, to accurately predict airflow and elucidate the underlying pulmonary pathology.

Imaging

2017 ◽  
Author(s):  
Robert Laureno
Keyword(s):  
Resonance Imaging ◽  
Cross Sectional ◽  
Advantages And Disadvantages ◽  
Mri Scans ◽  
Cross Sectional Imaging ◽  
Magnetic Resonance Imaging Mri ◽  
Cellular Pathology ◽  
Brain And Spinal Cord ◽  
The Brain

This chapter on “Imaging” examines the relative advantages and disadvantages of computed tomography (CT) and magnetic resonance imaging (MRI) scans. It compares the modalities to each other and to gross neuropathology. For several decades, neurologists have been able to view cross-sectional images of living patients. Analogous to gross neuropathology, cross-sectional imaging displays the brain as an entire organ but does not demonstrate microscopic tissue or cellular pathology. By allowing practitioners to view sections of brain and spinal cord in vivo, imaging has improved neurologic practice and facilitated clinical research. This chapter deals with imaging topics that are important to the neurologist. The timing of scans, the effects of gravity, and the importance of plane of section are considered. Imaging is compared to gross neuropathology, and MRI is compared to CT.

scholarly journals Increased contrast of the grey-white matter boundary in the motor, visual and auditory areas in Autism Spectrum Disorders

2019 ◽  
Author(s):  
Marion Fouquet ◽  
Nicolas Traut ◽  
Anita Beggiato ◽  
Richard Delorme ◽  
Thomas Bourgeron ◽  
...  
Keyword(s):  
White Matter ◽  
Data Exchange ◽  
Primary Motor Cortex ◽  
Autism Spectrum ◽  
Imaging Data ◽  
Sensory Motor ◽  
Magnetic Resonance Imaging Mri ◽  
Brain Imaging Data

AbstractThe contrast of the interface between the neocortical grey matter and the white matter is emerging as an important neuroimaging phenotype for several brain disorders. To date, a single in vivo study has analysed the cortical grey-to-white matter percent contrast (GWPC) on Magnetic Resonance Imaging (MRI), and has shown a significant decrease of this contrast in several areas in individuals with Autism Spectrum Disorder (ASD). Our goal was to replicate this study across a larger cohort, using the multicenter data from the Autism Brain Imaging Data Exchange 1 and 2 gathering data from 2,148 subjects. Multiple linear regression was used to study the effect of the diagnosis of ASD on the GWPC. Contrary to the first study, we found a statistically significant increase of GWPC among individuals with ASD in left auditory and bilateral visual sensory areas, as well as in the left primary motor cortex. These results were still statistically significant after inclusion of cortical thickness as covariate. There are numerous reports of sensory-motor atypicalities in patients with ASD, which may be the reason for the differences in GWPC that we observed. Further investigation could help us determine the potential role of a defect or a delay in intra-cortical myelination of sensory-motor regions in ASD. Code: https://github.com/neuroanatomy/GWPC.

Correlation between chronic headaches and the rectus capitis posterior minor muscle: A comparative analysis of cross-sectional trail

Cephalalgia ◽  
2016 ◽  
Vol 37 (11) ◽  
pp. 1051-1056 ◽  
Author(s):  
Xiao-Ying Yuan ◽  
Sheng-Bo Yu ◽  
Cong Liu ◽  
Qiang Xu ◽  
Nan Zheng ◽  
...  
Keyword(s):  
Healthy Adult ◽  
Morphological Changes ◽  
Control Group ◽  
Resonance Imaging ◽  
Cross Sectional ◽  
Magnetic Resonance Imaging Mri ◽  
Chronic Headaches ◽  
Adult Volunteers ◽  
Number Of Males ◽  
Minor Muscle

Objective We aimed to investigate the morphological changes and potential correlation between chronic headaches and the rectus capitis posterior minor muscle (RCPmi). Methods Comparison of RCPmi between patients with chronic headaches and healthy adult volunteers were collected using magnetic resonance imaging (MRI) and Mimics software. Results Among the 235 MRI images analyzed, the data between the two groups were considered statistically significant. The number of males was larger than that of females ( p < 0.001) and the headache group showed greater hypertrophy than the control group in both males ( p < 0.001) and females ( p = 0.001). Conclusions Chronic headaches were correlated with the RCPmi. Patients with chronic headaches suffered from more obvious hypertrophy than that of the control group. Additionally, it was supposed that RCPmi hypertrophy may be one pathogenesis of the chronic headaches.

scholarly journals Systemic Administration of Polyelectrolyte Microcapsules: Where Do They Accumulate and When? In Vivo and Ex Vivo Study

Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 812 ◽  
Author(s):  
Nikita Navolokin ◽  
Sergei German ◽  
Alla Bucharskaya ◽  
Olga Godage ◽  
Viktor Zuev ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Magnetite Nanoparticles ◽  
Ex Vivo ◽  
Morphological Changes ◽  
Morphological Structure ◽  
Intravenous Injections ◽  
Inner Organs ◽  
Distribution In Organs ◽  
Magnetic Resonance Imaging Mri

Multilayer capsules of 4 microns in size made of biodegradable polymers and iron oxide magnetite nanoparticles have been injected intravenously into rats. The time-dependent microcapsule distribution in organs was investigated in vivo by magnetic resonance imaging (MRI) and ex vivo by histological examination (HE), atomic absorption spectroscopy (AAS) and electron spin resonance (ESR), as these methods provide information at different stages of microcapsule degradation. The following organs were collected: Kidney, liver, lung, and spleen through 15 min, 1 h, 4 h, 24 h, 14 days, and 30 days after intravenous injections (IVIs) of microcapsules in a saline buffer at a dosage of 2.5 × 109 capsule per kg. The IVI of microcapsules resulted in reversible morphological changes in most of the examined inner organs (kidney, heart, liver, and spleen). The capsules lost their integrity due to degradation over 24 h, and some traces of iron oxide nanoparticles were seen at 7 days in spleen and liver structure. The morphological structure of the tissues was completely restored one month after IVI of microcapsules. Comprehensive analysis of the biodistribution and degradation of entire capsules and magnetite nanoparticles as their components gave us grounds to recommend these composite microcapsules as useful and safe tools for drug delivery applications.

Compression Garment-induced Leg Changes Increase Hemodynamic Responses in Healthy Individuals

2019 ◽  
Vol 41 (01) ◽  
pp. 3-11 ◽  
Author(s):  
Daniel C. W. Lee ◽  
Helen Ka Wai Law ◽  
Ajmol Ali ◽  
Sinead E. Sheridan ◽  
Stephen H. S. Wong ◽  
...  
Keyword(s):  
Lower Limb ◽  
Morphological Changes ◽  
Subcutaneous Fat ◽  
Lower Body ◽  
Healthy Individuals ◽  
Hemodynamic Responses ◽  
Cross Sectional ◽  
Physically Active ◽  
Hemodynamic Variables ◽  
Magnetic Resonance Imaging Mri

AbstractThis study evaluated the morphological changes of the lower limb and associated hemodynamic responses to different lower-body compression pressures (COMPs) in physically active, healthy individuals at rest. Each of the 32 participants underwent three trials with three different degrees of lower-body compression applied: “Low” (2.2±1.4 mmHg), “Medium” (12.9±3.9 mmHg), and “High” (28.8±8.3 mmHg). In each COMP, a cross-sectional area of leg muscles (CSAmuscle), subcutaneous fat (CSAfat), superficial vessels (SupV), deep arteries (DA), and deep veins (DV) at the calf, knee, and thigh levels were measured using magnetic resonance imaging (MRI). Additionally, blood pressure (BP), heart rate (HR), cardiac output (CO), stroke volume (SV), and systemic vascular resistance (SVR) were measured using Doppler ultrasound (USCOM®). With High COMP, calf CSAmuscle and SupV were smaller (p<0.01), whereas DA and DV were larger (p<0.05). Calf CSAfat, however, was similar among all COMPs. There were no major changes in CSAmuscle and CSAfat at knee and thigh levels. CO (3.2±0.9 L/min) and SV (51.9±16.4 mL) were higher (p<0.05) only with High COMP, but other hemodynamic variables showed no significant changes across different COMPs. The High COMP at the lower limb induces leg morphological changes and increases associated hemodynamic responses of physically active healthy individuals at rest.

scholarly journals Influence of aging on the in vivo properties of human patellar tendon

2008 ◽  
Vol 105 (6) ◽  
pp. 1907-1915 ◽  
Author(s):  
C. C. Carroll ◽  
J. M. Dickinson ◽  
J. M. Haus ◽  
G. A. Lee ◽  
C. J. Hollon ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Patellar Tendon ◽  
Signal Intensity ◽  
Knee Extensors ◽  
Stress And Strain ◽  
Force Output ◽  
Cross Sectional ◽  
Magnetic Resonance Imaging Mri ◽  
Deformation Stress

Tendons are important for optimal muscle force transfer to bone and play a key role in functional ability. Changes in tendon properties with aging could contribute to declines in physical function commonly associated with aging. We investigated the in vivo mechanical properties of the patellar tendon in 37 men and women [11 young (27 ± 1 yr) and 26 old (65 ± 1 yr)] using ultrasonography and magnetic resonance imaging (MRI). Patella displacement relative to the tibia was monitored with ultrasonography during ramped isometric contractions of the knee extensors, and MRI was used to determine tendon cross-sectional area (CSA) and signal intensity. At peak force, patellar tendon deformation, stress, and strain were 13 ( P = 0.05), 19, and 12% less in old compared with young ( P < 0.05). Additionally, deformation, stiffness, stress, CSA, and length were 18, 35, 41, 28, and 11% greater ( P < 0.05), respectively, in men compared with women. After normalization of mechanical properties to a common force, no age differences were apparent; however, stress and strain were 26 and 22% higher, respectively, in women compared with men ( P < 0.05). CSA and signal intensity decreased 12 and 24%, respectively, with aging ( P < 0.05) in the midregion of the tendon. These data suggest that differences in patellar tendon in vivo mechanical properties with aging are more related to force output rather than an age effect. In contrast, the decrease in signal intensity indirectly suggests that the internal milieu of the tendon is altered with aging; however, the physiological and functional consequence of this finding requires further study.

scholarly journals Inferring Functional Neural Connectivity with Deep Residual Convolutional Networks

2017 ◽  
Author(s):  
Timothy W. Dunn ◽  
Peter K. Koo
Keyword(s):  
Network Architecture ◽  
Correlation Coefficients ◽  
Real Data ◽  
Future Application ◽  
Imaging Data ◽  
Multiple Gpus ◽  
Convolutional Networks ◽  
Model Free ◽  
Brain Imaging Data

Measuring synaptic connectivity in large neuronal populations remains a major goal of modern neuroscience. While this connectivity is traditionally revealed by anatomical methods such as electron microscopy, an efficient alternative is to computationally infer functional connectivity from recordings of neural activity. However, these statistical techniques still require further refinement before they can be reliably applied to real data. Here, we report significant improvements to a deep learning method for functional connectomics, as assayed on synthetic ChaLearn Connectomics data. The method, which integrates recent advances in convolutional neural network architecture and model-free partial correlation coefficients, outperforms published methods on competition data and can achieve over 90% precision at 1% recall on validation datasets. This suggests that future application of the model to in vivo whole-brain imaging data in larval zebrafish could reliably recover on the order of 106 synaptic connections with a 10% false discovery rate. The model also generalizes to networks with different underlying connection probabilities and should scale well when parallelized across multiple GPUs. The method offers real potential as a statistical complement to existing experiments and circuit hypotheses in neuroscience.

scholarly journals Mitotic disassembly of the Golgi apparatus in vivo

1995 ◽  
Vol 108 (7) ◽  
pp. 2715-2727 ◽  
Author(s):  
T. Misteli ◽  
G. Warren
Keyword(s):  
Golgi Apparatus ◽  
Morphological Changes ◽  
Temperature Sensitive ◽  
Cross Sectional ◽  
Mitotic Kinase ◽  
Transport Vesicles ◽  
A Cell ◽  
Cell Cycle Block ◽  
Conventional Electron Microscopy

Populations enriched in prophase cells were obtained either by using a cell line with a temperature-sensitive mutation in the mitotic kinase, p34cdc2, or by treating cells with olomoucine, an inhibitor of this kinase. Both methods resulted in efficient and reversible block of the cells at the G2/M boundary. After cells were released from the cell cycle block, the morphological changes to the Golgi apparatus were characterised using both quantitative conventional electron microscopy and immuno-gold microscopy. The early mitotic phases were divided into six stages (G2 to pro-metaphase) based on the morphology of the nucleus. During prophase the cross-sectional length of Golgi stacks decreased prior to unstacking. At the same time, small vesicular profiles, typically 50–70 nm in diameter, accumulated in the vicinity of the stacks. The disappearance of Golgi stacks was accompanied by the transient appearance of tubular networks. By the time cells entered prometaphase, the stacks had completely disassembled and only clusters consisting of Golgi vesicles and short tubular elements were left. When cells were released from the G2/M boundary and pulsed briefly with [AlF4]- to prevent uncoating of transport vesicles, vesicular profiles with a morphology reminiscent of COP-coated vesicles appeared. These vesicular profiles were either associated with Golgi stacks or, at later stages, with clusters, but were formed at all stages of disassembly. Together these results provide further support for our model that continued budding of vesicles from the rims of Golgi cisternae is at least partly responsible for the disassembly of the Golgi apparatus.

scholarly journals Dynamic mechanical oscillations during metamorphosis of the monarch butterfly

2008 ◽  
Vol 6 (30) ◽  
pp. 29-37 ◽  
Author(s):  
Andrew E Pelling ◽  
Paul R Wilkinson ◽  
Richard Stringer ◽  
James K Gimzewski
Keyword(s):  
Structural Changes ◽  
Morphological Changes ◽  
Danaus Plexippus ◽  
Monarch Butterfly ◽  
Mechanical Quality Factor ◽  
Beam Deflection ◽  
Mechanical Oscillation ◽  
Insect Metamorphosis ◽  
Magnetic Resonance Imaging Mri

The mechanical oscillation of the heart is fundamental during insect metamorphosis, but it is unclear how morphological changes affect its mechanical dynamics. Here, the micromechanical heartbeat with the monarch chrysalis ( Danaus plexippus ) during metamorphosis is compared with the structural changes observed through in vivo magnetic resonance imaging (MRI). We employ a novel ultra-sensitive detection approach, optical beam deflection, in order to measure the microscale motions of the pupae during the course of metamorphosis. We observed very distinct mechanical contractions occurring at regular intervals, which we ascribe to the mechanical function of the heart organ. Motion was observed to occur in approximately 15 min bursts of activity with frequencies in the 0.4–1.0 Hz range separated by periods of quiescence during the first 83 per cent of development. In the final stages, the beating was found to be uninterrupted until the adult monarch butterfly emerged. Distinct stages of development were characterized by changes in frequency, amplitude, mechanical quality factor and de/repolarization times of the mechanical pulsing. The MRI revealed that the heart organ remains functionally intact throughout metamorphosis but undergoes morphological changes that are reflected in the mechanical oscillation.

Ultrastructural Study of a differentiating human colon carcinoma cell line

1990 ◽  
Vol 48 (3) ◽  
pp. 208-209
Author(s):  
Sylvie Polak-Charcon ◽  
Mehrdad Hekmati ◽  
Yehuda Ben Shaul
Keyword(s):  
Cell Line ◽  
Morphological Changes ◽  
Secretory Granules ◽  
Human Colon ◽  
Cell Types ◽  
Culture Conditions ◽  
Morphological Evidence ◽  
Human Colon Carcinoma Cell ◽  
Colon Cell

The epithelium of normal human colon mucosa “in vivo” exhibits a gradual pattern of differentiation as undifferentiated stem cells from the base of the crypt of “lieberkuhn” rapidly divide, differentiate and migrate toward the free surface. The major differentiated cell type of the intestine observed are: absorptive cells displaying brush border, goblet cells containing mucous granules, Paneth and endocrine cells containing dense secretory granules. These different cell types are also found in the intestine of the 13-14 week old embryo.We present here morphological evidence showing that HT29, an adenocarcinoma of the human colon cell line, can differentiate into various cell types by changing the growth and culture conditions and mimic morphological changes found during development of the intestine in the human embryo.HT29 cells grown in tissue-culture dishes in DMEM and 10% FCS form at late confluence a multilayer of morphologically undifferentiated cell culture covered with irregular microvilli, and devoid of tight junctions (Figs 1-3).

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