scholarly journals Study of Osteocyte Behavior by High-Resolution Intravital Imaging Following Photo-Induced Ischemia

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2874
Author(s):  
Hengfeng Yuan ◽  
Wen Jiang ◽  
Yuanxin Chen ◽  
Betty Kim
Keyword(s):  
Imaging Techniques ◽  
Avascular Osteonecrosis ◽  
Functional Changes ◽  
Cellular Processes ◽  
Non Invasive ◽  
Behavioral Dynamics ◽  
Bony Anatomy ◽  
Magnetic Resonance Imaging Mri

Ischemic injuries and local hypoxia can result in osteocytes dysfunction and play a key role in the pathogenesis of avascular osteonecrosis. Conventional imaging techniques including magnetic resonance imaging (MRI) and computed tomography (CT) can reveal structural and functional changes within bony anatomy; however, characterization of osteocyte behavioral dynamics in the setting of osteonecrosis at the single cell resolution is limited. Here, we demonstrate an optical approach to study real-time osteocyte functions in vivo. Using nicotinamide adenine dinucleotide (NADH) as a biomarker for metabolic dynamics in osteocytes, we showed that NADH level within osteocytes transiently increase significantly after local ischemia through non-invasive photo-induced thrombosis of afferent arterioles followed by a steady decline. Our study presents a non-invasive optical approach to study osteocyte behavior through the modulation of local environmental conditions. Thus it provides a powerful toolkit to study cellular processes involved in bone pathologies in vivo.

scholarly journals Watching cellular machinery in action, one molecule at a time

2016 ◽  
Vol 216 (1) ◽  
pp. 41-51 ◽  
Author(s):  
Enrico Monachino ◽  
Lisanne M. Spenkelink ◽  
Antoine M. van Oijen
Keyword(s):  
Dynamic Behavior ◽  
Single Molecule ◽  
Protein Complexes ◽  
Imaging Techniques ◽  
Ensemble Averaging ◽  
Cellular Processes ◽  
Cellular Machinery

Single-molecule manipulation and imaging techniques have become important elements of the biologist’s toolkit to gain mechanistic insights into cellular processes. By removing ensemble averaging, single-molecule methods provide unique access to the dynamic behavior of biomolecules. Recently, the use of these approaches has expanded to the study of complex multiprotein systems and has enabled detailed characterization of the behavior of individual molecules inside living cells. In this review, we provide an overview of the various force- and fluorescence-based single-molecule methods with applications both in vitro and in vivo, highlighting these advances by describing their applications in studies on cytoskeletal motors and DNA replication. We also discuss how single-molecule approaches have increased our understanding of the dynamic behavior of complex multiprotein systems. These methods have shown that the behavior of multicomponent protein complexes is highly stochastic and less linear and deterministic than previously thought. Further development of single-molecule tools will help to elucidate the molecular dynamics of these complex systems both inside the cell and in solutions with purified components.

scholarly journals Clinical application of pet

2005 ◽  
Vol 48 (spe2) ◽  
pp. 179-183 ◽  
Author(s):  
Francisco Lomeña ◽  
Marina Soler
Keyword(s):  
Structural Information ◽  
Imaging Modality ◽  
Imaging Techniques ◽  
Neurological Diseases ◽  
Efficiency Ratio ◽  
Non Invasive ◽  
Positron Emission ◽  
Pet Ct ◽  
Magnetic Resonance Imaging Mri

Positron emission tomography (PET) is an imaging modality that gives information on tissue metabolism and functionalism, different from other imaging techniques like computed tomography (CT) and magnetic resonance imaging (MRI), which provide anatomical or structural information. PET has reached its development in biomedical research because of its capacity to use analogous compounds of many endogenous substance as tracers, and to measure, in vivo and in a non-invasive way, their consumption by the different organs and tissues of the mammalian body. Fluordeoxyglucose-F18 (FDG) PET has been proven to be a tracer adequate for clinical use in oncology and in many neurological diseases, with an excellent cost-efficiency ratio. The current PET-CT scanners can come to be the best tools for exploring patients who suffer from cancer.

scholarly journals Non-invasive diagnostics in fossils - Magnetic Resonance Imaging of pathological belemnites

2005 ◽  
Vol 2 (2) ◽  
pp. 133-140 ◽  
Author(s):  
D. Mietchen ◽  
H. Keupp ◽  
B. Manz ◽  
F. Volke
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Soft Tissue ◽  
Clinical Diagnostics ◽  
Resonance Imaging ◽  
Non Invasive ◽  
Physiological Processes ◽  
Magnetic Resonance Imaging Mri ◽  
Invasive Diagnostics

Abstract. For more than a decade, Magnetic Resonance Imaging (MRI) has been routinely employed in clinical diagnostics because it allows non-invasive studies of anatomical structures and physiological processes in vivo and to differentiate between healthy and pathological states, particularly of soft tissue. Here, we demonstrate that MRI can likewise be applied to fossilized biological samples and help in elucidating paleopathological and paleoecological questions: Five anomalous guards of Jurassic and Cretaceous belemnites are presented along with putative paleopathological diagnoses directly derived from 3D MR images with microscopic resolution. Syn vivo deformities of both the mineralized internal rostrum and the surrounding former soft tissue can be traced back in part to traumatic events of predator-prey-interactions, and partly to parasitism. Besides, evidence is presented that the frequently observed anomalous apical collar might be indicative of an inflammatory disease. These findings highlight the potential of Magnetic Resonance techniques for further paleontological applications.

scholarly journals Current Trends in Non-Invasive Imaging of Interactions in the Liver Tumor Microenvironment Mediated by Tumor Metabolism

Cancers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 3645
Author(s):  
Isabel Theresa Schobert ◽  
Lynn Jeanette Savic
Keyword(s):  
Tumor Microenvironment ◽  
Liver Cancer ◽  
Cancer Cells ◽  
Imaging Techniques ◽  
Treatment Strategies ◽  
Tumor Metabolism ◽  
Resistance Mechanisms ◽  
Metabolic Reprogramming ◽  
Non Invasive

With the increasing understanding of resistance mechanisms mediated by the metabolic reprogramming in cancer cells, there is a growing clinical interest in imaging technologies that allow for the non-invasive characterization of tumor metabolism and the interactions of cancer cells with the tumor microenvironment (TME) mediated through tumor metabolism. Specifically, tumor glycolysis and subsequent tissue acidosis in the realms of the Warburg effect may promote an immunosuppressive TME, causing a substantial barrier to the clinical efficacy of numerous immuno-oncologic treatments. Thus, imaging the varying individual compositions of the TME may provide a more accurate characterization of the individual tumor. This approach can help to identify the most suitable therapy for each individual patient and design new targeted treatment strategies that disable resistance mechanisms in liver cancer. This review article focuses on non-invasive positron-emission tomography (PET)- and MR-based imaging techniques that aim to visualize the crosstalk between tumor cells and their microenvironment in liver cancer mediated by tumor metabolism.

scholarly journals In Vivo Imaging of Biodegradable Implants and Related Tissue Biomarkers

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2348
Author(s):  
Leon Riehakainen ◽  
Chiara Cavallini ◽  
Paolo Armanetti ◽  
Daniele Panetta ◽  
Davide Caramella ◽  
...  
Keyword(s):  
Imaging Modality ◽  
Imaging Techniques ◽  
Special Focus ◽  
Tissue Remodelling ◽  
Biodegradable Implant ◽  
Advantages And Disadvantages ◽  
Non Invasive ◽  
Positron Emission ◽  
Longitudinal Imaging

Non-invasive longitudinal imaging of osseointegration of bone implants is essential to ensure a comprehensive, physical and biochemical understanding of the processes related to a successful implant integration and its long-term clinical outcome. This study critically reviews the present imaging techniques that may play a role to assess the initial stability, bone quality and quantity, associated tissue remodelling dependent on implanted material, implantation site (surrounding tissues and placement depth), and biomarkers that may be targeted. An updated list of biodegradable implant materials that have been reported in the literature, from metal, polymer and ceramic categories, is provided with reference to the use of specific imaging modalities (computed tomography, positron emission tomography, ultrasound, photoacoustic and magnetic resonance imaging) suitable for longitudinal and non-invasive imaging in humans. The advantages and disadvantages of the single imaging modality are discussed with a special focus on preclinical imaging for biodegradable implant research. Indeed, the investigation of a new implant commonly requires histological examination, which is invasive and does not allow longitudinal studies, thus requiring a large number of animals for preclinical testing. For this reason, an update of the multimodal and multi-parametric imaging capabilities will be here presented with a specific focus on modern biomaterial research.

Hyperpolarized 129Xe Magnetic Resonance Spectroscopy in a Rat Model of Bronchopulmonary Dysplasia

2021 ◽  
Author(s):  
Jordan David Fliss ◽  
Brandon Zanette ◽  
Yonni Friedlander ◽  
Siddharth Sadanand ◽  
Andras A Lindenmaier ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Gas Exchange ◽  
Magnetic Resonance Spectroscopy ◽  
Bronchopulmonary Dysplasia ◽  
Rat Model ◽  
Resonance Spectroscopy ◽  
Gas Exchange Parameters ◽  
Functional Changes ◽  
Non Invasive

Premature infants often require mechanical ventilation and oxygen therapy which can result in bronchopulmonary dysplasia (BPD), characterized by developmental arrest and impaired lung function. Conventional clinical methods for assessing the prenatal lung are not adequate for the detection and assessment of long-term health risks in infants with BPD, highlighting the need for a non-invasive tool for the characterization of lung microstructure and function. Theoretical diffusion models, like the Model of Xenon Exchange (MOXE), interrogate alveolar gas exchange by predicting the uptake of inert Hyperpolarized (HP) 129Xe gas measured with HP 129Xe magnetic resonance spectroscopy (MRS). To investigate HP 129Xe MRS as a tool for non-invasive characterization of pulmonary microstructural and functional changes in vivo, HP 129Xe gas exchange data were acquired in an oxygen exposure rat model of BPD that recapitulates the fewer and larger distal airways and pulmonary vascular stunting characteristics of BPD. Gas exchange parameters from MOXE, including airspace mean chord length (L­m), apparent hematocrit in the pulmonary capillaries (HCT), and pulmonary capillary transit time (tx), were compared with airspace mean axis length and area density (MAL and ρ­A) and percentage area of tissue and air (PTA and PAA) from histology. L­m was significantly larger in the exposed rats (p=0.003) and correlated with MAL, ρ­A, PTA, and PAA (0.59<|ρ|<0.66 and p<0.05). Observed increase in HCT (p=0.012) and changes in tx are also discussed. These findings support the use of HP 129Xe MRS for detecting fewer, enlarged distal airways in this rat model of BPD, and potentially in humans.

scholarly journals In vivo imaging techniques: a new era for histochemical analysis

2016 ◽  
Author(s):  
A. Busato ◽  
P. Fumene Feruglio ◽  
P.P. Parnigotto ◽  
P. Marzola ◽  
A. Sbarbati
Keyword(s):  
Magnetic Resonance ◽  
In Vivo Imaging ◽  
Diffusion Tensor ◽  
Technological Development ◽  
Imaging Techniques ◽  
Resonance Spectroscopy ◽  
Preclinical Research ◽  
Tissue Contrast ◽  
Magnetic Resonance Imaging Mri

In vivo imaging techniques can be integrated with classical histochemistry to create an actual histochemistry of water. In particular, Magnetic Resonance Imaging (MRI), an imaging technique primarily used as diagnostic tool in clinical/preclinical research, has excellent anatomical resolution, unlimited penetration depth and intrinsic soft tissue contrast. Thanks to the technological development, MRI is not only capable to provide morphological information but also and more interestingly functional, biophysical and molecular. In this paper we describe the main features of several advanced imaging techniques, such as MRI microscopy, Magnetic Resonance Spectroscopy, functional MRI, Diffusion Tensor Imaging and MRI with contrast agent as a useful support to classical histochemistry.

Medical Imaging of the Airway

2019 ◽  
Author(s):  
Gilbert S Tang
Keyword(s):  
Foreign Body ◽  
Medical Imaging ◽  
Mediastinal Mass ◽  
Imaging Techniques ◽  
Traumatic Injury ◽  
Spine Injury ◽  
Non Invasive ◽  
Faraday’S Law ◽  
Magnetic Resonance Imaging Mri ◽  
Abnormal Anatomy

Non-invasive imaging techniques such as ultrasonography, x-ray, computerized tomography (CT) and magnetic resonance imaging (MRI) provide details about airway anatomy that complement the physical examination. They are of particular value in patients with traumatic injury, malignancy, abscess, foreign body or mass in the airway that displace, distort, disrupt, encroach or compress airway structures in ways that may not be readily apparent otherwise. Many anesthesiologists do not receive formal training in interpreting medical imaging, and a thorough discussion of this subject is beyond the scope of this review. Interpreting the subtleties of normal and abnormal anatomy require years of experience and best left to expert radiologists. The goal here is to introduce the imaging techniques available and examples of clinical applications in airway evaluation of interest to the anesthesiologist. This review contains 12 figures, 2 tables, and 37 references. Keywords: piezoelectric effect, photoelectric interaction, Faraday’s law, pneumothorax, cervical spine injury, LeFort fracture, foreign body, airway infection, mediastinal mass

EEG Based Detection of Alcoholics

2019 ◽  
pp. 141-160
Author(s):  
T. K. Padma Shri ◽  
N. Sriraam
Keyword(s):  
Human Brain ◽  
Imaging Techniques ◽  
Cost Effective ◽  
The Body ◽  
Long Term Effects ◽  
Non Invasive ◽  
Positron Emission ◽  
Signal Processing Algorithms ◽  
Magnetic Resonance Imaging Mri ◽  
Neuro Imaging

The short term and long term effects of alcohol on various organs of the body, especially on the human brain is well established by numerous studies. Invasive methods such as Transcranial Magnetic Stimulation (TMS) and non invasive imaging techniques such as Computed Tomography (CT), Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET), and functional MRI activated electro-encephalogram (EEG) have been used to study the changes in EEG activity due to alcoholism. Even with the advent of neuro imaging techniques, EEG happens to be an important tool for brain study providing a non- invasive and cost effective method to detect the effects of alcohol on the human brain. This paper discusses the harmful effects of alcohol on different organs of the body. The advances in the development of EEG signal processing algorithms over the past decade for alcoholic detection are reviewed and their limitations are reported. Further the use of EEG for mass screening of alcoholics and biometric application is discussed in detail.

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