Development and In vivo Validation of an MR-Compatible Temperature Controllable Superficial Hyperthermia Applicator for Small Animal Studies

2018 ◽  
Author(s):  
Kemal Sumser ◽  
Anthony Geerman ◽  
Joost Haeck ◽  
Monique Bernsen ◽  
Gerard C. van Rhoon ◽  
...  
Keyword(s):  
Animal Studies ◽  
Small Animal ◽  
Superficial Hyperthermia ◽  
In Vivo Validation

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 Sleep Dependent Changes of Lactate Concentration in Human Brain

2021 ◽  
Author(s):  
Selda Yildiz ◽  
Miranda M. Lim ◽  
Manoj K. Sammi ◽  
Katherine Powers ◽  
Charles F. Murchison ◽  
...  
Keyword(s):  
Human Brain ◽  
Rem Sleep ◽  
Animal Studies ◽  
Sleep Stage ◽  
Lactate Concentration ◽  
Small Animal ◽  
Resonance Spectroscopy ◽  
Non Invasive ◽  
Brain Lactate

AbstractLactate is an important cellular metabolite that is present at high concentrations in the brain, both within cells and in the extracellular space between cells. Small animal studies demonstrated high extracellular concentrations of lactate during wakefulness with reductions during sleep and/or anesthesia with a recent study suggesting the glymphatic activity as the mechanism for the reduction of lactate concentrations. We have recently developed a rigorous non-invasive imaging approach combining simultaneous magnetic resonance spectroscopy (MRS) and polysomnography (PSG) measurements, and here, we present the first in-vivo evaluation of brain lactate levels during sleep-wake cycles in young healthy humans. First, we collected single voxel proton MRS (1H-MRS) data at the posterior cingulate with high temporal resolution (every 7.5 sec), and simultaneously recorded PSG data while temporally registering with 1H-MRS time-series. Second, we evaluated PSG data in 30 s epochs, and classified into four stages Wake (W), Non-REM sleep stage 1 (N1), Non-REM sleep stage 2 (N2), and Non-REM sleep stage 3 (N3). Third, we determined lactate signal intensity from each 7.5-s spectrum, normalized to corresponding water signal, and averaged over 30-s for each PSG epoch. In examinations of nine healthy participants (four females, five males; mean age 24.2 (±2; SD) years; age range: 21-27 years) undergoing up to 3-hour simultaneous MRS/PSG recordings, we observed a group mean reduction of [4.9 ± 4.9] % in N1, [10.4 ± 5.2] % in N2, and [24.0 ± 5.8] % in N3 when compared to W. Our finding is consistent with more than 70 years of invasive lactate measurements from small animal studies. In addition, reduced brain lactate was accompanied by a significant reduction the apparent diffusion coefficient of brain lactate. Taken together, these findings are consistent with the loss of lactate from the extracellular space during sleep while suggesting lactate metabolism is altered and/or lactate clearance via glymphatic exchange is increased during sleep.Significance StatementThis study describes a non-invasive magnetic resonance spectroscopy/polysomnography technique that allows rigorous measurement of brain metabolite levels together with simultaneous characterization of brain arousal state as either wakeful or one of the several sleep states. The results provide the first in-vivo demonstration of reductions in brain lactate concentration and diffusivity during sleep versus wakefulness in young healthy human brain. These findings are consistent with invasive small-animal studies showing the loss of extracellular lactate during sleep, and support the notion of altered lactate metabolism and/or increased glymphatic activity in sleeping human brain.

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.

Decellularized bone extracellular matrix in skeletal tissue engineering

2020 ◽  
Vol 48 (3) ◽  
pp. 755-764
Author(s):  
Benjamin B. Rothrauff ◽  
Rocky S. Tuan
Keyword(s):  
Tissue Engineering ◽  
Bone Regeneration ◽  
Tissue Regeneration ◽  
Animal Studies ◽  
Tumor Resection ◽  
Regenerative Capacity ◽  
Skeletal Tissue ◽  
Large Bone

Bone possesses an intrinsic regenerative capacity, which can be compromised by aging, disease, trauma, and iatrogenesis (e.g. tumor resection, pharmacological). At present, autografts and allografts are the principal biological treatments available to replace large bone segments, but both entail several limitations that reduce wider use and consistent success. The use of decellularized extracellular matrices (ECM), often derived from xenogeneic sources, has been shown to favorably influence the immune response to injury and promote site-appropriate tissue regeneration. Decellularized bone ECM (dbECM), utilized in several forms — whole organ, particles, hydrogels — has shown promise in both in vitro and in vivo animal studies to promote osteogenic differentiation of stem/progenitor cells and enhance bone regeneration. However, dbECM has yet to be investigated in clinical studies, which are needed to determine the relative efficacy of this emerging biomaterial as compared with established treatments. This mini-review highlights the recent exploration of dbECM as a biomaterial for skeletal tissue engineering and considers modifications on its future use to more consistently promote bone regeneration.

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