scholarly journals Follow Me! A Tale of Avian Heart Development with Comparisons to Mammal Heart Development

2020 ◽  
Vol 7 (1) ◽  
pp. 8 ◽  
Author(s):  
Rusty Lansford ◽  
Sandra Rugonyi
Keyword(s):  
Heart Development ◽  
Avian Embryos ◽  
Non Invasive ◽  
Heart Formation ◽  
Ease Of Access ◽  
Invasive Techniques ◽  
Further Development ◽  
Chicken Development ◽  
Study Development

Avian embryos have been used for centuries to study development due to the ease of access. Because the embryos are sheltered inside the eggshell, a small window in the shell is ideal for visualizing the embryos and performing different interventions. The window can then be covered, and the embryo returned to the incubator for the desired amount of time, and observed during further development. Up to about 4 days of chicken development (out of 21 days of incubation), when the egg is opened the embryo is on top of the yolk, and its heart is on top of its body. This allows easy imaging of heart formation and heart development using non-invasive techniques, including regular optical microscopy. After day 4, the embryo starts sinking into the yolk, but still imaging technologies, such as ultrasound, can tomographically image the embryo and its heart in vivo. Importantly, because like the human heart the avian heart develops into a four-chambered heart with valves, heart malformations and pathologies that human babies suffer can be replicated in avian embryos, allowing a unique developmental window into human congenital heart disease. Here, we review avian heart formation and provide comparisons to the mammalian heart.

scholarly journals Non-Invasive Assessment of Intravascular Pressure Gradients: A Review of Current and Proposed Novel Methods

Diagnostics ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 5 ◽  
Author(s):  
Tin-Quoc Nguyen ◽  
Kristoffer Hansen ◽  
Thor Bechsgaard ◽  
Lars Lönn ◽  
Jørgen Jensen ◽  
...  
Keyword(s):  
Stokes Equations ◽  
Imaging Techniques ◽  
Navier Stokes ◽  
Pressure Gradients ◽  
Bernoulli Equation ◽  
Strong Correlations ◽  
Navier Stokes Equations ◽  
Non Invasive ◽  
Invasive Techniques

Invasive catheterization is associated with a low risk of serious complications. However, although it is the gold standard for measuring pressure gradients, it induces changes to blood flow and requires significant resources. Therefore, non-invasive alternatives are urgently needed. Pressure gradients are routinely estimated non-invasively in clinical settings using ultrasound and calculated with the simplified Bernoulli equation, a method with several limitations. A PubMed literature search on validation of non-invasive techniques was conducted, and studies were included if non-invasively estimated pressure gradients were compared with invasively measured pressure gradients in vivo. Pressure gradients were mainly estimated from velocities obtained with Doppler ultrasound or magnetic resonance imaging. Most studies used the simplified Bernoulli equation, but more recent studies have employed the expanded Bernoulli and Navier–Stokes equations. Overall, the studies reported good correlation between non-invasive estimation of pressure gradients and catheterization. Despite having strong correlations, several studies reported the non-invasive techniques to either overestimate or underestimate the invasive measurements, thus questioning the accuracy of the non-invasive methods. In conclusion, more advanced imaging techniques may be needed to overcome the shortcomings of current methods.

scholarly journals Non-Invasive Continuous Measurement of Haemodynamic Parameters—Clinical Utility

2021 ◽  
Vol 10 (21) ◽  
pp. 4929
Author(s):  
Aleksandra Bodys-Pełka ◽  
Maciej Kusztal ◽  
Maria Boszko ◽  
Renata Główczyńska ◽  
Marcin Grabowski
Keyword(s):  
Clinical Utility ◽  
Everyday Clinical Practice ◽  
Non Invasive ◽  
Haemodynamic Parameters ◽  
Cardiac Procedures ◽  
New Findings ◽  
Evaluation And Monitoring ◽  
Invasive Techniques ◽  
Further Development ◽  
Invasive Measurement

The evaluation and monitoring of patients’ haemodynamic parameters are essential in everyday clinical practice. The application of continuous, non-invasive measurement methods is a relatively recent solution. CNAP, ClearSight and many other technologies have been introduced to the market. The use of these techniques for assessing patient eligibility before cardiac procedures, as well as for intraoperative monitoring is currently being widely investigated. Their numerous advantages, including the simplicity of application, time- and cost-effectiveness, and the limited risk of infection, could enforce their further development and potential utility. However, some limitations and contradictions should also be discussed. The aim of this paper is to briefly describe the new findings, give practical examples of the clinical utility of these methods, compare them with invasive techniques, and review the literature on this subject.

scholarly journals A Bright Future for Fluorescence Imaging of Fungi in Living Hosts

2019 ◽  
Vol 5 (2) ◽  
pp. 29 ◽  
Author(s):  
Ambre Chapuis ◽  
Elizabeth Ballou ◽  
Donna MacCallum
Keyword(s):  
Mouse Models ◽  
Fluorescent Proteins ◽  
Imaging Techniques ◽  
Post Mortem ◽  
New Techniques ◽  
Ethical Concerns ◽  
Non Invasive ◽  
Reporter Proteins ◽  
Invasive Techniques

Traditional in vivo investigation of fungal infection and new antifungal therapies in mouse models is usually carried out using post mortem methodologies. However, biomedical imaging techniques focusing on non-invasive techniques using bioluminescent and fluorescent proteins have become valuable tools. These new techniques address ethical concerns as they allow reduction in the number of animals required to evaluate new antifungal therapies. They also allow better understanding of the growth and spread of the pathogen during infection. In this review, we concentrate on imaging technologies using different fungal reporter proteins. We discuss the advantages and limitations of these different reporters and compare the efficacy of bioluminescent and fluorescent proteins for fungal research.

In vivo study of scleroderma by non-invasive techniques

1990 ◽  
Vol 122 (6) ◽  
pp. 785-791 ◽  
Author(s):  
B. KALIS ◽  
J. RIGAL ◽  
F. LEONARD ◽  
J.L. LEVEQUE ◽  
O. RICHE ◽  
...  
Keyword(s):  
In Vivo Study ◽  
Non Invasive ◽  
Invasive Techniques

scholarly journals Anterior visual system imaging to investigate energy failure in multiple sclerosis

Brain ◽  
2020 ◽  
Vol 143 (7) ◽  
pp. 1999-2008 ◽  
Author(s):  
Iris Kleerekooper ◽  
Axel Petzold ◽  
S Anand Trip
Keyword(s):  
Multiple Sclerosis ◽  
Visual System ◽  
Adaptive Optics ◽  
Mitochondrial Function ◽  
Structural Changes ◽  
Future Research ◽  
Optical Coherence ◽  
Non Invasive ◽  
Invasive Techniques

Abstract Mitochondrial failure and hypoxia are key contributors to multiple sclerosis pathophysiology. Importantly, improving mitochondrial function holds promise as a new therapeutic strategy in multiple sclerosis. Currently, studying mitochondrial changes in multiple sclerosis is hampered by a paucity of non-invasive techniques to investigate mitochondrial function of the CNS in vivo. It is against this backdrop that the anterior visual system provides new avenues for monitoring of mitochondrial changes. The retina and optic nerve are among the metabolically most active structures in the human body and are almost always affected to some degree in multiple sclerosis. Here, we provide an update on emerging technologies that have the potential to indirectly monitor changes of metabolism and mitochondrial function. We report on the promising work with optical coherence tomography, showing structural changes in outer retinal mitochondrial signal bands, and with optical coherence angiography, quantifying retinal perfusion at the microcapillary level. We show that adaptive optics scanning laser ophthalmoscopy can visualize live perfusion through microcapillaries and structural changes at the level of single photoreceptors and neurons. Advantages and limitations of these techniques are summarized with regard to future research into the pathology of the disease and as trial outcome measures.

Vertebrate tinman homologues XNkx2-3 and XNkx2-5 are required for heart formation in a functionally redundant manner

Development ◽  
1998 ◽  
Vol 125 (22) ◽  
pp. 4439-4449 ◽  
Author(s):  
Y. Fu ◽  
W. Yan ◽  
T.J. Mohun ◽  
S.M. Evans
Keyword(s):  
Gene Family ◽  
Heart Development ◽  
Functional Redundancy ◽  
Homeodomain Protein ◽  
Dna Encoding ◽  
Cardiac Phenotype ◽  
Novel Approach ◽  
Heart Formation ◽  
Mutant Phenotypes

Tinman is a Drosophila homeodomain protein that is required for formation of both visceral and cardiac mesoderm, including formation of the dorsal vessel, a heart-like organ. Although several vertebrate tinman homologues have been characterized, their requirement in earliest stages of heart formation has been an open question, perhaps complicated by potential functional redundancy of tinman homologues. We have utilized a novel approach to investigate functional redundancy within a gene family, by coinjecting DNA encoding dominantly acting repressor derivatives specific for each family member into developing Xenopus embryos. Our results provide the first evidence that vertebrate tinman homologues are required for earliest stages of heart formation, and that they are required in a functionally redundant manner. Coinjection of dominant repressor constructs for both XNkx2-3 and XNkx2-5 is synergistic, resulting in a much higher frequency of mutant phenotypes than that obtained with injection of either dominant repressor construct alone. Rescue of mutant phenotypes can be effected by coinjection of either wild-type tinman homologue. The most extreme mutant phenotype is a complete absence of expression of XNkx2-5 in cardiogenic mesoderm, an absence of markers of differentiated myocardium, and absence of morphologically distinguishable heart on the EnNkxHD-injected side of the embryo. This phenotype represents the most severe cardiac phenotype of any vertebrate mutant yet described, and underscores the importance of the tinman family for heart development. These results provide the first in vivo evidence that XNkx2-3 and XNkx2-5 are required as transcriptional activators for the earliest stages of heart formation. Furthermore, our results suggest an intriguing mechanism by which functional redundancy operates within a gene family during development. Our experiments have been performed utilizing a recently developed transgenic strategy, and attest to the efficacy of this strategy for enabling transgene expression in limited cell populations within the developing Xenopus embryo.

scholarly journals Tailoring the surface charge of dextran-based polymer coated SPIONs for modulated stem cell uptake and MRI contrast

2015 ◽  
Vol 3 (4) ◽  
pp. 608-616 ◽  
Author(s):  
Michael Barrow ◽  
Arthur Taylor ◽  
Daniel J. Nieves ◽  
Lara K. Bogart ◽  
Pranab Mandal ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Surface Charge ◽  
Cell Uptake ◽  
Efficacy And Safety ◽  
Mri Contrast ◽  
Non Invasive ◽  
Invasive Techniques

Tracking stem cells in vivo using non-invasive techniques is critical to evaluate their efficacy and safety.

scholarly journals Reporter gene-based optoacoustic imaging of E. coli targeted colon cancer in vivo

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Misun Yun ◽  
Sung-Hwan You ◽  
Vu Hong Nguyen ◽  
Jaya Prakash ◽  
Sarah Glasl ◽  
...  
Keyword(s):  
Tumor Imaging ◽  
Bacterial Colonization ◽  
Optoacoustic Imaging ◽  
E Coli ◽  
Non Invasive ◽  
Endogenous Contrast ◽  
Further Development ◽  
Engineered Bacteria ◽  
Cancer Targeted Therapy

AbstractBacteria-mediated cancer-targeted therapy is a novel experimental strategy for the treatment of cancers. Bacteria can be engineered to overcome a major challenge of existing therapeutics by differentiating between malignant and healthy tissue. A prerequisite for further development and study of engineered bacteria is a suitable imaging concept which allows bacterial visualization in tissue and monitoring bacterial targeting and proliferation. Optoacoustics (OA) is an evolving technology allowing whole-tumor imaging and thereby direct observation of bacterial colonization in tumor regions. However, bacterial detection using OA is currently hampered by the lack of endogenous contrast or suitable transgene fluorescent labels. Here, we demonstrate improved visualization of cancer-targeting bacteria using OA imaging and E. coli engineered to express tyrosinase, which uses L-tyrosine as the substrate to produce the strong optoacoustic probe melanin in the tumor microenvironment. Tumors of animals injected with tyrosinase-expressing E. coli showed strong melanin signals, allowing to resolve bacterial growth in the tumor over time using multispectral OA tomography (MSOT). MSOT imaging of melanin accumulation in tumors was confirmed by melanin and E. coli staining. Our results demonstrate that using tyrosinase-expressing E. coli enables non-invasive, longitudinal monitoring of bacterial targeting and proliferation in cancer using MSOT.

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