scholarly journals Visualization capabilities of experimental oncological models in small laboratory animals

2018 ◽  
Vol 9 (4) ◽  
pp. 105-112 ◽  
Author(s):  
Valeria A. Pechatnikova ◽  
Alexander P. Trashkov ◽  
Maria A. Zelenenko ◽  
Nikolay A. Verlov ◽  
Grigorii A. Chizh ◽  
...  
Keyword(s):  
Soft Tissues ◽  
Pathological Process ◽  
Nerve Fibers ◽  
Laboratory Animals ◽  
Small Laboratory ◽  
Internal Organs ◽  
Imaging Methods ◽  
Non Invasive ◽  
Long Time

For a long time non-invasive imaging methods have been inaccessible in preclinical practice; their introduction lately has broadened the boundaries of relevant studies and felicitated new approaches to solving fundamental problems. Up-to-date imaging methods constitute an essential component of preclinical and translational biomedical research allowing quick and non-invasive extended representation of structural organization and functional characteristics of pathological processes in vivo. Methods of radiation diagnosis and nuclear magnetic resonance allow to assess the state of bones, soft tissues, internal organs, blood vessels and peripheral nerve fibers in various animals, not only mammals, but also fish, amphibians, reptiles and insects. Multiparametric studies can uniquely localize any anatomical structure or pathological process. However, not all existing techniques are applicable to various oncological models of small laboratory animals.

Non-Invasive Measurement of In-Vivo Elasticity of Skeletal Muscles with MR-Elastography

2007 ◽  
Vol 342-343 ◽  
pp. 901-904
Author(s):  
Yu Bong Kang ◽  
T. Oida ◽  
Duk Young Jung ◽  
A. Fukuma ◽  
T. Azuma ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Modulus ◽  
Skeletal Muscles ◽  
Soft Tissues ◽  
Viscosity Coefficient ◽  
Non Invasive ◽  
Novel Method ◽  
Human Calf ◽  
Invasive Measurement

In order to evaluate the mechanical properties of the human skeletal muscles, the elasticity and viscosity of the human calf muscles were measured with Magnetic Resonance Elastography (MRE). MRE is a novel method to measure the mechanical properties of living soft tissues in vivo quantitatively by observing the strain waves propagated in the object. In this study, the shear modulus and viscosity coefficient were measured with MRE. The shear modulus was 3.7 kPa in relaxed state, and increased with increasing the muscle forces. Interestingly, the viscosity was changed with the vibration frequency applied to the muscles, that was 4.5 Pa·s at 100Hz vibration and 2.4 Pa·s at 200Hz vibration. This shows clearly the visco-elastic property.

scholarly journals Why Are Viscosity and Nonlinearity Bound to Make an Impact in Clinical Elastographic Diagnosis?

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2379 ◽  
Author(s):  
Guillermo Rus ◽  
Inas H. Faris ◽  
Jorge Torres ◽  
Antonio Callejas ◽  
Juan Melchor
Keyword(s):  
Soft Tissues ◽  
Elastic Parameters ◽  
Tissue Microstructure ◽  
Non Invasive ◽  
Recent Developments ◽  
Mechanical Biomarkers ◽  
Nonlinear Elastic

The adoption of multiscale approaches by the biomechanical community has caused a major improvement in quality in the mechanical characterization of soft tissues. The recent developments in elastography techniques are enabling in vivo and non-invasive quantification of tissues’ mechanical properties. Elastic changes in a tissue are associated with a broad spectrum of pathologies, which stems from the tissue microstructure, histology and biochemistry. This knowledge is combined with research evidence to provide a powerful diagnostic range of highly prevalent pathologies, from birth and labor disorders (prematurity, induction failures, etc.), to solid tumors (e.g., prostate, cervix, breast, melanoma) and liver fibrosis, just to name a few. This review aims to elucidate the potential of viscous and nonlinear elastic parameters as conceivable diagnostic mechanical biomarkers. First, by providing an insight into the classic role of soft tissue microstructure in linear elasticity; secondly, by understanding how viscosity and nonlinearity could enhance the current diagnosis in elastography; and finally, by compounding preliminary investigations of those elastography parameters within different technologies. In conclusion, evidence of the diagnostic capability of elastic parameters beyond linear stiffness is gaining momentum as a result of the technological and imaging developments in the field of biomechanics.

Nasal cavity dimensions in guinea pig and rat measured by acoustic rhinometry and fluid-displacement method

2004 ◽  
Vol 96 (6) ◽  
pp. 2109-2114 ◽  
Author(s):  
Sune P. Straszek ◽  
Ole F. Pedersen
Keyword(s):  
Nasal Cavity ◽  
Guinea Pigs ◽  
Acoustic Rhinometry ◽  
Laboratory Animals ◽  
Small Laboratory ◽  
Acoustic Measurements ◽  
Displacement Method ◽  
Fluid Displacement ◽  
Custom Made

The purpose of the study was to measure nasal passageway dimensions in guinea pigs and rats by use of acoustic rhinometry (AR) and by a previously described fluid-displacement method (FDM) (Straszek SP, Taagehoej F, Graff S, and Pedersen OF. J Appl Physiol 95: 635–642, 2003) to investigate the potential of AR in pharmacological research with these animals. We measured the area-distance relationships by AR of nasal cavities postmortem in five guinea pigs (Duncan Hartley, 400 g) and five rats (Wistar, 250 g) by using custom-made equipment scaled for the purpose. Nosepieces were made from plastic pipette tips and either inserted into or glued onto the nostrils. We used liquid perfluorocarbon in the fluid-displacement study, and it was carried out subsequent to the acoustic measurements. We found for guinea pigs that AR measured a mean volume of 98 mm3 (95–100 mm3) (mean and 95% confidence interval) of the first 2 cm of the cavity. FDM measured a mean volume of 146 mm3 (117–175 mm3), meaning that AR only measured 70% (50–90) of the volume by FDM. For rats, the volume from 0 to 2 cm was 58 mm3 (55–61 mm3) by AR and 73 mm3 (60–87 mm3) by FDM, resulting in AR only measuring 83% (66–100%) of volume by FDM (see Table 2 ). We conclude that absolute nasal cavity dimensions are underestimated by AR in guinea pigs and rats. This does not preclude that relative changes may be correctly measured. In vivo trials with AR using rats have not yet been published. The FDM is possibly the most accurate alternative to AR for measurements of the nasal cavity geometry in small laboratory animals, but it can only be used postmortem.

scholarly journals Foregut organ progenitors and their niche display distinct viscoelastic properties in vivo during early morphogenesis stages

2021 ◽  
Author(s):  
Aliaksandr Dzementsei ◽  
Younes F. A Barooji ◽  
Elke A Ober ◽  
Lene Broeng Oddershede
Keyword(s):  
Optical Tweezers ◽  
Material Properties ◽  
Biological Function ◽  
Living Matter ◽  
Internal Organs ◽  
Neighboring Cell ◽  
Invasive Approach ◽  
Non Invasive

Material properties of living matter play an important role for biological function and development. Yet, quantification of material properties of internal organs in vivo, without causing physiological damage, remains challenging. Here, we present a non-invasive approach based on modified optical tweezers for quantifying sub-cellular material properties deep inside living zebrafish. Material properties of cells within the gut region of living zebrafish are quantified as deep as 150 μ into the biological tissue. The measurements demonstrate differential mechanical properties of the developing foregut organs progenitors: Gut progenitors are more elastic than any of the neighboring cell populations at the time when the developing organs undergo substantial displacements during morphogenesis. The higher elasticity of gut progenitors correlates with an increased cellular concentration of microtubules. The results infer a role of material properties during morphogenesis and the approach paves the way for quantitative material investigations in vivo of embryos, explants, or organoids.

scholarly journals Analysis of the Effect of Nd:YAG Laser Irradiation on Soft Tissues of the Oral Cavity in Different Modes in an In Vivo Experiment

2021 ◽  
Vol 12 (3) ◽  
pp. 2881-2888
Keyword(s):  
Oral Cavity ◽  
Nd:Yag Laser ◽  
Soft Tissues ◽  
Surgical Techniques ◽  
Healing Time ◽  
Pulse Action ◽  
Laboratory Animals ◽  
Laser Medicine ◽  
Study Results

The development of laser medicine has led to its use in dentistry further to improve existing treatment methods, including surgical techniques. The variety of lasers allows them to be used for procedures on the soft and bone tissues of the oral cavity as well as on the tissues of the teeth. The short duration of laser pulse action on tissues, selective action on pathological tissues in a sterile surgical field, and activation of local and humoral immunity of the oral cavity provides an increase in the regeneration potential of tissues of the postoperative area, which contributes to the shortening of wound process phases, favorable course of the postoperative period, and shortening of the healing time. Our article presents the experience of using the Nd:YAG laser in different modes in replicating the effect of curettage of periodontal pockets in an experiment on laboratory animals. According to the study results, there was a difference in the healing time of soft tissues after their exposure to several modes of the Nd:YAG laser, which makes it possible to recommend each of them for individual clinical cases.

High-resolution light microscopy of living organs in situ

1995 ◽  
Vol 53 ◽  
pp. 790-791
Author(s):  
R. S. McCuskey
Keyword(s):  
High Resolution ◽  
Light Microscopy ◽  
Laboratory Animals ◽  
Small Laboratory ◽  
Abdominal Incision ◽  
Standard Compound ◽  
Working Distance ◽  
Microscope Stage

Most organs in anesthetized small laboratory animals can be studied in vivo by light microscopy of relatively thin (3-5mm), transilluminated areas of the organ. Thicker areas of the organs in these species, as well as thicker organs of larger animals can be examined only by epi-ilumination. However, the resolution obtainable with epi-ilumination usually is inferior to that realized with transillumination. This paper reviews these methods using the liver as an example of the organ of study. A standard compound trinocular microscope is used which is modified for in vivo microscopy and is equipped for both transillumination and epi-illumination. After the animal is anesthetized, the liver is gently exteriorized through a subcostal, abdominal incision and positioned over a window of optical grade mica or glass on a specially designed, heated microscope stage having provisions for draining irrigation fluids. The window overlies a long working distance condenser. The liver is covered by a piece of Saran or Mylar film which holds it in position and limits movements induced by respiration, the heart and the intestines.

scholarly journals Non-invasive detection of protein metabolism in vivo by n.m.r. spectroscopy. Application of a novel 19F-containing residualizing label

1989 ◽  
Vol 264 (3) ◽  
pp. 829-835 ◽  
Author(s):  
A Daugherty ◽  
N N Becker ◽  
L A Scherrer ◽  
B E Sobel ◽  
J J H Ackerman ◽  
...  
Keyword(s):  
Intravenous Administration ◽  
Half Life ◽  
Soft Tissues ◽  
Degradation Products ◽  
Chemical Shifts ◽  
Whole Body ◽  
Hepatic Tissue ◽  
Protein Accumulation ◽  
Non Invasive

Protein residualizing labels facilitate localization of tissue sites of protein catabolism and the quantification of protein accumulation because of their prolonged intracellular retention of protein accumulation because of their prolonged intracellular retention times. Radioiodinated residualizing labels have been used to define the metabolism of a wide variety of proteins, but this has necessitated destructive analysis. Here we describe the implementation and validation of a novel 19F-containing residualizing label for protein, NN-dilactitol-3,5-bis(trifluoromethyl)benzylamine (DLBA), that permits the non-invasive assessment of protein accumulation and catabolism by n.m.r. spectroscopy in vivo. DLBA comprises a reporter molecule containing six equivalent 19F atoms. 19F is strongly n.m.r.-active, has 100% natural abundance, and is present in minimal background concentrations in soft tissues. We validated the use of DLBA as a protein-labelling compound by coupling to asialofetuin (ASF), a protein that is recognized exclusively by hepatic tissue via a saturable receptor-mediated process. Coupling of DLBA to ASF by reductive amination had no effect on the physiological receptor-mediated uptake of the protein in rat liver in vivo. The 19F-n.m.r. spectrum of DLBA exhibited a single peak that was subject to a small chemical-shift change and broadening after coupling to ASF. Pronase digestion of DLBA-ASF was performed to simulate intracellular degradation products, and resulted in a narrower set of resonances, with chemical shifts intermediate between those of uncoupled DLBA and DLBA-ASF. Intravenous administration of DLBA-ASF to rats followed by quantification of 19F in homogenates of liver tissue indicated that the half-life of residence time of degradation products from DLBA-ASF in liver was approx. 2 days. This intracellular half-life was comparable with that described for similar residualizing labels that contain radioiodide as a reporter. Similar results for the half-life of retention were obtained non-destructively and non-invasively in situ with the use of a whole-body radio-frequency antenna to acquire sequential spectra over 80 h after intravenous administration of DLBA-ASF. Quantification of these spectra demonstrated an initial accumulation of DLBA-ASF in liver followed by an expected gradual loss of 19F-labelled degradation products. The approach developed offers promise for the sequential and longitudinal characterization of metabolism of specific proteins in individual experimental animals and ultimately in human subjects.

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