scholarly journals In Vivo Measurement of Fine and Coarse Aerosol Deposition in the Nasal Airways of Female Long-Evans Rats

2001 ◽  
Vol 64 (2) ◽  
pp. 253-258 ◽  
Author(s):  
J. T. Kelly
Keyword(s):  
Aerosol Deposition ◽  
Nasal Airways ◽  
In Vivo Measurement ◽  
Long Evans ◽  
Coarse Aerosol

scholarly journals Plastinated nasal model: a new concept of anatomically realistic cast

2011 ◽  
Vol 49 (1) ◽  
pp. 30-36
Author(s):  
Marc Durand ◽  
Jeremie Pourchez ◽  
Bruno Louis ◽  
Jean Francois Pouget ◽  
Daniel Isabey ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Aerosol Deposition ◽  
Nasal Airways ◽  
Nasal Cavities ◽  
Aerodynamic Properties ◽  
Anatomy Laboratory ◽  
High Level ◽  
Nasal Flow

BACKGROUND: For many years, researchers have been interested in investigating airflow and aerosol deposition in the nasal cavities. The nasal airways appear to be a complex geometrical system. Thus, in vitro experimental studies are frequently conducted with a more or less biomimetic nasal replica. AIM: This study is devoted to the development of an anatomically realistic nose model with bilateral nasal cavities, i.e. nasal anatomy, airway geometry and aerodynamic properties as close as possible to in vivo behaviour. METHODS: A specific plastination technique of cephalic extremities was developed by the Anatomy Laboratory at the Saint-Etienne University in the last 10 years. The plastinated models obtained were anatomically, geometrically and aerodynamically validated using several techniques (endoscopy, CT scans, acoustic rhinometry and rhinomanometry). RESULTS: Our plastination model exhibited a high level of anatomic quality, including a very good mucosa preservation. Aerodynamical and geometrical investigations highlighted a global behaviour of plastinated models perfectly in accordance with a nasal decongested healthy subject. CONCLUSIONS: The present plastination model provides a realistic cast of nasal airways, and may be a useful tool for nasal flow, drug delivery and aerosol deposition studies.

scholarly journals In Vivo Measurement of Neurochemical Abnormalities in the Hippocampus in a Rat Model of Cuprizone-Induced Demyelination

Diagnostics ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 45
Author(s):  
Do-Wan Lee ◽  
Jae-Im Kwon ◽  
Chul-Woong Woo ◽  
Hwon Heo ◽  
Kyung Won Kim ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Rat Model ◽  
Resonance Spectroscopy ◽  
Chow Diet ◽  
Gamma Aminobutyric Acid ◽  
Sprague Dawley ◽  
In Vivo Measurement ◽  
Hippocampal Lesions ◽  
Total Creatine

This study quantitatively measured the changes in metabolites in the hippocampal lesions of a rat model of cuprizone-induced demyelination as detected using in vivo 7 T proton magnetic resonance spectroscopy. Nineteen Sprague Dawley rats were randomly divided into two groups and fed a normal chow diet or cuprizone (0.2%, w/w) for 7 weeks. Demyelinated hippocampal lesions were quantitatively measured using a 7 T magnetic resonance imaging scanner. All proton spectra were quantified for metabolite concentrations and relative ratios. Compared to those in the controls, the cuprizone-induced rats had significantly higher concentrations of glutamate (p = 0.001), gamma-aminobutyric acid (p = 0.019), and glutamate + glutamine (p = 0.001); however, creatine + phosphocreatine (p = 0.006) and myo-inositol (p = 0.001) concentrations were lower. In addition, we found that the glutamine and glutamate complex/total creatine (p < 0.001), glutamate/total creatine (p < 0.001), and GABA/total creatine (p = 0.002) ratios were significantly higher in cuprizone-treated rats than in control rats. Our results showed that cuprizone-induced neuronal demyelination may influence the severe abnormal metabolism in hippocampal lesions, and these responses could be caused by microglial activation, mitochondrial dysfunction, and astrocytic necrosis.

scholarly journals Towards planning of osteotomy around the knee with quantitative inclusion of the adduction moment: a biomechanical approach

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Margit Biehl ◽  
Philipp Damm ◽  
Adam Trepczynski ◽  
Stefan Preiss ◽  
Gian Max Salzmann
Keyword(s):  
Gait Analysis ◽  
Measurement Data ◽  
Frontal Plane ◽  
Medial Compartment ◽  
Knee Adduction Moment ◽  
In Vivo Measurement ◽  
Force Ratio ◽  
Leg Alignment ◽  
Alignment Angle

Abstract Purpose Despite practised for decades, the planning of osteotomy around the knee, commonly using the Mikulicz-Line, is only empirically based, clinical outcome inconsistent and the target angle still controversial. A better target than the angle of frontal-plane static leg alignment might be the external frontal-plane lever arm (EFL) of the knee adduction moment. Hypothetically assessable from frontal-plane-radiograph skeleton dimensions, it might depend on the leg-alignment angle, the hip-centre-to-hip-centre distance, the femur- and tibia-length. Methods The target EFL to achieve a medial compartment force ratio of 50% during level-walking was identified by relating in-vivo-measurement data of knee-internal loads from nine subjects with instrumented prostheses to the same subjects’ EFLs computed from frontal-plane skeleton dimensions. Adduction moments derived from these calculated EFLs were compared to the subjects’ adduction moments measured during gait analysis. Results Highly significant relationships (0.88 ≤ R2 ≤ 0.90) were found for both the peak adduction moment measured during gait analysis and the medial compartment force ratio measured in vivo to EFL calculated from frontal-plane skeleton dimensions. Both correlations exceed the respective correlations with the leg alignment angle, EFL even predicts the adduction moment’s first peak. The guideline EFL for planning osteotomy was identified to 0.349 times the epicondyle distance, hence deducing formulas for individualized target angles and Mikulicz-Line positions based on full-leg radiograph skeleton dimensions. Applied to realistic skeleton geometries, widespread results explain the inconsistency regarding correction recommendations, whereas results for average geometries exactly meet the most-consented “Fujisawa-Point”. Conclusion Osteotomy outcome might be improved by planning re-alignment based on the provided formulas exploiting full-leg-radiograph skeleton dimensions.

scholarly journals SARS-CoV-2-Laden Respiratory Aerosol Deposition in the Lung Alveolar-Interstitial Region Is a Potential Risk Factor for Severe Disease: A Modeling Study

2021 ◽  
Vol 11 (5) ◽  
pp. 431
Author(s):  
Sabine Hofer ◽  
Norbert Hofstätter ◽  
Albert Duschl ◽  
Martin Himly
Keyword(s):  
Risk Factor ◽  
Particle Deposition ◽  
Early Stage ◽  
Severe Disease ◽  
Ambient Air ◽  
Aerosol Deposition ◽  
Pulmonary Involvement ◽  
Mild Disease ◽  
Disease Initiation

COVID-19, predominantly a mild disease, is associated with more severe clinical manifestation upon pulmonary involvement. Virion-laden aerosols and droplets target different anatomical sites for deposition. Compared to droplets, aerosols more readily advance into the peripheral lung. We performed in silico modeling to confirm the secondary pulmonary lobules as the primary site of disease initiation. By taking different anatomical aerosol origins into consideration and reflecting aerosols from exhalation maneuvers breathing and vocalization, the physicochemical properties of generated respiratory aerosol particles were defined upon conversion to droplet nuclei by evaporation at ambient air. To provide detailed, spatially-resolved information on particle deposition in the thoracic region of the lung, a top-down refinement approach was employed. Our study presents evidence for hot spots of aerosol deposition in lung generations beyond the terminal bronchiole, with a maximum in the secondary pulmonary lobules and a high preference to the lower lobes of both lungs. In vivo, initial chest CT anomalies, the ground glass opacities, resulting from partial alveolar filling and interstitial thickening in the secondary pulmonary lobules, are likewise localized in these lung generations, with the highest frequency in both lower lobes and in the early stage of disease. Hence, our results suggest a disease initiation right there upon inhalation of virion-laden respiratory aerosols, linking the aerosol transmission route to pathogenesis associated with higher disease burden and identifying aerosol transmission as a new independent risk factor for developing a pulmonary phase with a severe outcome.

In vivo measurement of velocity profiles in arterioles

2006 ◽  
Vol 142 (6) ◽  
pp. 748-750 ◽  
Author(s):  
V. A. Mamisashvili ◽  
N. T. Mchedlishvili ◽  
E. T. Chachanidze ◽  
K. N. Urotadze ◽  
M. V. Gongadze
Keyword(s):  
Velocity Profiles ◽  
In Vivo Measurement

scholarly journals Cervical cord myelin abnormality is associated with clinical disability in multiple sclerosis

2021 ◽  
pp. 135245852110017
Author(s):  
Lisa Eunyoung Lee ◽  
Irene M Vavasour ◽  
Adam Dvorak ◽  
Hanwen Liu ◽  
Shawna Abel ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Progressive Multiple Sclerosis ◽  
Dorsal Column ◽  
Cervical Cord ◽  
In Vivo Measurement ◽  
Subclinical Disease ◽  
Healthy Control ◽  
Magnetic Resonance Imaging Mri ◽  
Relapsing Remitting Multiple Sclerosis

Background: Myelin water imaging (MWI) was recently optimized to provide quantitative in vivo measurement of spinal cord myelin, which is critically involved in multiple sclerosis (MS) disability. Objective: To assess cervical cord myelin measurements in relapsing-remitting multiple sclerosis (RRMS) and progressive multiple sclerosis (ProgMS) participants and evaluate the correlation between myelin measures and clinical disability. Methods: We used MWI data from 35 RRMS, 30 ProgMS, and 28 healthy control (HC) participants collected at cord level C2/C3 on a 3 T magnetic resonance imaging (MRI) scanner. Myelin heterogeneity index (MHI), a measurement of myelin variability, was calculated for whole cervical cord, global white matter, dorsal column, lateral and ventral funiculi. Correlations were assessed between MHI and Expanded Disability Status Scale (EDSS), 9-Hole Peg Test (9HPT), timed 25-foot walk, and disease duration. Results: In various regions of the cervical cord, ProgMS MHI was higher compared to HC (between 9.5% and 31%, p ⩽ 0.04) and RRMS (between 13% and 26%, p ⩽ 0.02), and ProgMS MHI was associated with EDSS ( r = 0.42–0.52) and 9HPT ( r = 0.45–0.52). Conclusion: Myelin abnormalities within clinically eloquent areas are related to clinical disability. MWI metrics have a potential role for monitoring subclinical disease progression and adjudicating treatment efficacy for new therapies targeting ProgMS.

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