scholarly journals Tendon mechanobiology in small-animal experiments during post-transection healing

2021 ◽  
Vol 42 ◽  
pp. 375-391
Author(s):  
T Notermans ◽  
◽  
M Hammerman ◽  
P Eliasson ◽  
H Isaksson
Keyword(s):  
Animal Studies ◽  
Animal Experiments ◽  
Tendon Healing ◽  
Small Animal ◽  
Tendon Regeneration ◽  
Appropriate Treatment ◽  
Temporal Differentiation ◽  
Rats And Mice ◽  
In Vivo Loading

Ruptures to tendons are common and costly, and no clinical consensus exists on the appropriate treatment and rehabilitation regimen to promote their healing as well as full recovery of functionality. Although mechanobiology is known to play an important role in tendon regeneration, the understanding of how mechano-regulated processes affect tendon healing needs further clarification. Many small-animal studies, particularly in rats and mice, have characterized the progression of healing in terms of geometrical, structural, compositional, mechanical, and cellular properties. Some of the properties are also studied under different mechanical loading regimens. The focus of this review is to summarize and generalize the information in the literature regarding spatial and temporal differentiation of tendon properties during rodent tendon healing following full-tendon transection, as well as how this is affected by altered in vivo loading regimens.

scholarly journals A novel method optimizing the normalization of cardiac parameters in small animal models: the importance of dimensional indexing

2019 ◽  
Vol 316 (6) ◽  
pp. H1552-H1557 ◽  
Author(s):  
Quint A. J. Hagdorn ◽  
Guido P. L. Bossers ◽  
Anne-Marie C. Koop ◽  
Arnold Piek ◽  
Tim R. Eijgenraam ◽  
...  
Keyword(s):  
Body Weight ◽  
Animal Models ◽  
Animal Experiments ◽  
Three Dimensional ◽  
Small Animal ◽  
Left Ventricular ◽  
Heart Weight ◽  
Small Animal Models ◽  
Rats And Mice ◽  
Tibia Length

For indexing cardiac measures in small animal models, tibia length (TL) is a recommended surrogate for body weight (BW) that aims to avoid biases because of disease-induced BW changes. However, we question if indexing by TL is mathematically correct. This study aimed to investigate the relation between TL and BW, heart weight, ventricular weights, and left ventricular diameter to optimize the current common practice of indexing cardiac parameters in small animal models. In 29 healthy Wistar rats (age 5–34 wk) and 116 healthy Black 6 mice (age 3–17 wk), BW appeared to scale nonlinearly to TL1 but linearly to TL3. Formulas for indexing cardiac weights were derived. To illustrate the effects of indexing, cardiac weights between the 50% with highest BW and the 50% with lowest BW were compared. The nonindexed cardiac weights differed significantly between groups, as could be expected ( P < 0.001). However, after indexing by TL1, indexed cardiac weights remained significantly different between groups ( P < 0.001). With the derived formulas for indexing, indexed cardiac weights were similar between groups. In healthy rats and mice, BW and heart weights scale linearly to TL3. This indicates that not TL1 but TL3 is the optimal surrogate for BW. New formulas for indexing heart weight and isolated ventricular weights are provided, and we propose a concept in which cardiac parameters should not all be indexed to the same measure but one-dimensional measures to BW1/3 or TL1, two-dimensional measures to BW2/3 or TL2, and three-dimensional measures to BW or TL3. NEW & NOTEWORTHY In healthy rats and mice, body weight (BW) scales linearly to tibia length (TL) to the power of three (TL3). This indicates that for indexing cardiac parameters, not TL1 but TL3 is the optimal surrogate for BW. New formulas for indexing heart weight and isolated ventricular weights are provided, and we propose a concept of dimensionally consistent indexing. This concept is proposed to be widely applied in small animal experiments.

Comparative pulmonary toxicity of inhaled metalworking fluids in rats and mice

2016 ◽  
Vol 33 (5) ◽  
pp. 385-405 ◽  
Author(s):  
Kristen R Ryan ◽  
Mark F Cesta ◽  
Ronald Herbert ◽  
Amy Brix ◽  
Michelle Cora ◽  
...  
Keyword(s):  
Animal Studies ◽  
Clinical Chemistry ◽  
Female Rats ◽  
Metalworking Fluids ◽  
Whole Body ◽  
Chemical Components ◽  
Male And Female ◽  
Male And Female Rats ◽  
Rats And Mice

Metalworking fluids (MWFs) are complex formulations designed for effective lubricating, cooling, and cleaning tools and parts during machining operations. Adverse health effects such as respiratory symptoms, dermatitis, and cancer have been reported in workers exposed to MWFs. Several constituents of MWFs have been implicated in toxicity and have been removed from the formulations over the years. However, animal studies with newer MWFs demonstrate that they continue to pose a health risk. This investigation examines the hypothesis that unrecognized health hazards exist in currently marketed MWF formulations that are presumed to be safe based on hazard assessments of individual ingredients. In vivo 13-week inhalation studies were designed to characterize and compare the potential toxicity of four MWFs: Trim VX, Cimstar 3800, Trim SC210, and Syntilo 1023. Male and female Wistar Han rats or Fischer 344N/Tac rats and B6C3F1/N mice were exposed to MWFs via whole-body inhalation at concentrations of 0, 25, 50, 100, 200, or 400 mg/m3 for 13 weeks, after which, survival, body and organ weights, hematology and clinical chemistry, histopathology, and genotoxicity were assessed following exposure. Although high concentrations were used, survival was not affected and toxicity was primarily within the respiratory tract of male and female rats and mice. Minor variances in toxicity were attributed to differences among species as well as in the chemical components of each MWF. Pulmonary fibrosis was present only in rats and mice exposed to Trim VX. These data confirm that newer MWFs have the potential to cause respiratory toxicity in workers who are repeatedly exposed via inhalation.

Development of a novel radiation imaging detector system for in vivo gene imaging in small animal studies

1998 ◽  
Vol 45 (3) ◽  
pp. 1743-1749 ◽  
Author(s):  
A.G. Weisenberger ◽  
E.L. Bradley ◽  
S. Majewski ◽  
M.S. Saha
Keyword(s):  
Animal Studies ◽  
Small Animal ◽  
Detector System ◽  
Radiation Imaging ◽  
Imaging Detector

scholarly journals Preliminary Experience with Small Animal SPECT Imaging on Clinical Gamma Cameras

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
P. Aguiar ◽  
J. Silva-Rodríguez ◽  
M. Herranz ◽  
A. Ruibal
Keyword(s):  
Animal Studies ◽  
Small Animal ◽  
Spect Imaging ◽  
Portable Device ◽  
Preclinical Research ◽  
Preclinical Imaging ◽  
Gamma Cameras ◽  
Widespread Availability ◽  
Phantom Experiments

The traditional lack of techniques suitable forin vivoimaging has induced a great interest in molecular imaging for preclinical research. Nevertheless, its use spreads slowly due to the difficulties in justifying the high cost of the current dedicated preclinical scanners. An alternative for lowering the costs is to repurpose old clinical gamma cameras to be used for preclinical imaging. In this paper we assess the performance of a portable device, that is, working coupled to a single-head clinical gamma camera, and we present our preliminary experience in several small animal applications. Our findings, based on phantom experiments and animal studies, provided an image quality, in terms of contrast-noise trade-off, comparable to dedicated preclinical pinhole-based scanners. We feel that our portable device offers an opportunity for recycling the widespread availability of clinical gamma cameras in nuclear medicine departments to be used in small animal SPECT imaging and we hope that it can contribute to spreading the use of preclinical imaging within institutions on tight budgets.

scholarly journals Attenuation Correction for Small Animal PET Images: A Comparison of Two Methods

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Daniela D'Ambrosio ◽  
Federico Zagni ◽  
Antonello E. Spinelli ◽  
Mario Marengo
Keyword(s):  
Attenuation Correction ◽  
Animal Studies ◽  
Spinal Column ◽  
Small Animal ◽  
Small Animal Pet ◽  
X Rays ◽  
Beam Hardening ◽  
Photon Attenuation ◽  
Bone Scans

In order to extract quantitative parameters from PET images, several physical effects such as photon attenuation, scatter, and partial volume must be taken into account. The main objectives of this work were the evaluation of photon attenuation in small animals and the implementation of two attenuation correction methods based on X-rays CT and segmentation of emission images. The accuracy of the first method with respect to the beam hardening effect was investigated by using Monte Carlo simulations. Mouse- and rat-sized phantoms were acquired in order to evaluate attenuation correction in terms of counts increment and recovery of uniform activity concentration. Both methods were applied to mice and rat images acquired with several radiotracers such asF18-FDG,11C-acetate,68Ga-chloride, andF18-NaF. The accuracy of the proposed methods was evaluated in heart and tumour tissues usingF18-FDG images and in liver, kidney, and spinal column tissues usingC11-acetate,Ga68-chloride, andF18-NaF images, respectively.In vivoresults from animal studies show that, except for bone scans, differences between the proposed methods were about 10% in rats and 3% in mice. In conclusion, both methods provide equivalent results; however, the segmentation-based approach has several advantages being less time consuming and simple to implement.

scholarly journals A Meta-Analysis of Resveratrol Protects against Myocardial Ischemia/Reperfusion Injury: Evidence from Small Animal Studies and Insight into Molecular Mechanisms

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Zhi-Jie Mao ◽  
Hui Lin ◽  
Jian-Wen Hou ◽  
Qian Zhou ◽  
Qian Wang ◽  
...  
Keyword(s):  
Myocardial Ischemia ◽  
Infarct Size ◽  
Animal Studies ◽  
Ex Vivo ◽  
Ischemia Reperfusion ◽  
Meta Analysis ◽  
Small Animal ◽  
Route Of Administration ◽  
Myocardial Ischemia Reperfusion

Aims. Myocardial ischemia/reperfusion (I/R) injury is a leading cause of cardiomyocyte loss and subsequent ventricular dysfunction after restoring the coronary blood flow and contributes to considerable increase in morbidity and mortality. Resveratrol has been declared to confer cardioprotection against in vivo and ex vivo myocardial I/R injury. Here, we have sought to investigate the effects of preconditioning with resveratrol on myocardial I/R damage across the small animal studies. Methods and Results. The MEDLINE, Google Scholar, PubMed, and Cochrane databases were searched for preclinical studies investigating resveratrol vs. vehicle published from the inception to July 2018. Eventually, 10 in vivo and 7 ex vivo studies with 261 animals (130 for resveratrol; 131 for vehicle) were included for meta-analysis. Pooled estimates for primary outcomes demonstrated that pretreatment with resveratrol significantly reduced the infarct size after myocardial I/R injury irrespective of in vivo (weighted mean difference (WMD): -13.42, 95% CI: -16.63 to -10.21, P≤0.001) or ex vivo (WMD: -15.05, 95% CI: -18.23 to -11.86, P≤0.001) studies. Consistently, stratified analysis according to the reperfusion duration, route of administration, or timing regimen of pretreatment all showed the infarct-sparing benefit of resveratrol. Metaregression did not indicate any difference in infarct size based on species, sample size, state, route of administration, reperfusion duration, and timing regimen of pretreatment. Meanwhile, sensitivity analysis also identified the cardioprotection of resveratrol with robust results in spite of significant heterogeneity. Conclusions. Preconditioning with resveratrol appears to prevent the heart from I/R injury in comparison with vehicle, as evidenced by limited infarct size in a preclinical setting. Studies with large animals or randomized controlled trials will add more evidence and provide the rationale for clinical use.

scholarly journals Mesenchymal Stem Cells Empowering Tendon Regenerative Therapies

2019 ◽  
Vol 20 (12) ◽  
pp. 3002 ◽  
Author(s):  
Raquel Costa-Almeida ◽  
Isabel Calejo ◽  
Manuela E. Gomes
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Tendon Repair ◽  
Tendon Healing ◽  
In Vivo Studies ◽  
Competent Cell ◽  
Tendon Regeneration ◽  
Regenerative Therapies

Tendon tissues have limited healing capacity. The incidence of tendon injuries and the unsatisfactory functional outcomes of tendon repair are driving the search for alternative therapeutic approaches envisioning tendon regeneration. Cellular therapies aim at delivering adequate, regeneration-competent cell types to the injured tendon and toward ultimately promoting its reconstruction and recovery of functionality. Mesenchymal stem cells (MSCs) either obtained from tendons or from non-tendon sources, like bone marrow (BM-MSCs) or adipose tissue (ASCs), have been receiving increasing attention over the years toward enhancing tendon healing. Evidences from in vitro and in vivo studies suggest MSCs can contribute to accelerate and improve the quality of tendon healing. Nonetheless, the exact mechanisms underlying these repair events are yet to be fully elucidated. This review provides an overview of the main challenges in the field of cell-based regenerative therapies, discussing the role of MSCs in boosting tendon regeneration, particularly through their capacity to enhance the tenogenic properties of tendon resident cells.

The Quality of Reporting Raises Questions on the Experimental Validity of Animal Studies Conducted in India and Sri Lanka: Preliminary Analysis of a Systematic Survey

2020 ◽  
Vol 48 (2) ◽  
pp. 85-91
Author(s):  
Vijay Pal Singh ◽  
Ayushi Jain ◽  
Shubhra Gupta ◽  
Manudharshy Vijayakumar ◽  
Kunal Pratap ◽  
...  
Keyword(s):  
Sri Lanka ◽  
Animal Studies ◽  
Peer Review Process ◽  
Animal Experiments ◽  
Sample Size Calculation ◽  
Quality Of Reporting ◽  
Systematic Survey ◽  
In Vivo Experiments

The quality of animal experiments in terms of appropriate reporting is a concern, particularly with regard to their validity and the recording of the measures taken to reduce various types of bias. A systematic survey of 1371 and 236 publications from India and Sri Lanka, respectively, which were published between 1905 and 2017 and indexed in NCBI-PubMed, Cinhal, MEDLINE and Scopus, was carried out. The level of detail in the descriptions of animals used and the measures taken to reduce bias were analysed in each article. Selected parameters from the Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines, such as age, weight, sex, sample size calculation, blinding and randomisation were considered. The findings revealed poor reporting standards in animal experiments carried out in India and Sri Lanka, confirming the limited impact of the ARRIVE guidelines. These findings emphasise the urgent need for improvements in the peer review process, both prior to a study being set up and in the post-study reporting phase, and for more stringent adherence to the ARRIVE guidelines in the reporting of animal experiments.

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