scholarly journals Modern Trends in Imaging XI: Impedance Measurements in the Biomedical Sciences

2012 ◽  
Vol 35 (5-6) ◽  
pp. 363-374 ◽  
Author(s):  
Frederick D. Coffman ◽  
Stanley Cohen
Keyword(s):  
High Throughput Screening ◽  
Single Cells ◽  
Whole Body ◽  
Measuring Instruments ◽  
Biomedical Sciences ◽  
Impedance Measurements ◽  
Cell Monolayers ◽  
Disease States ◽  
Progression Of Disease ◽  
Biological Organisms

Biological organisms and their component organs, tissues and cells have unique electrical impedance properties. Impedance properties often change with changes in structure, composition, and metabolism, and can be indicative of the onset and progression of disease states. Over the past 100 years, instruments and analytical methods have been developed to measure the impedance properties of biological specimens and to utilize these measurements in both clinical and basic science settings. This chapter will review the applications of impedance measurements in the biomedical sciences, from whole body analysis to impedance measurements of single cells and cell monolayers, and how cellular impedance measuring instruments can now be used in high throughput screening applications.

scholarly journals Seven Mathematical Models of Hemorrhagic Shock

2021 ◽  
Vol 2021 ◽  
pp. 1-34
Author(s):  
Luciano Curcio ◽  
Laura D'Orsi ◽  
Andrea De Gaetano
Keyword(s):  
Mathematical Models ◽  
Cardiovascular System ◽  
Experimental Situation ◽  
Hypovolemic Shock ◽  
Whole Body ◽  
Standards Of Care ◽  
Ideal Model ◽  
Disease States ◽  
Key Issues ◽  
Circulatory Dynamics

Although mathematical modelling of pressure-flow dynamics in the cardiocirculatory system has a lengthy history, readily finding the appropriate model for the experimental situation at hand is often a challenge in and of itself. An ideal model would be relatively easy to use and reliable, besides being ethically acceptable. Furthermore, it would address the pathogenic features of the cardiovascular disease that one seeks to investigate. No universally valid model has been identified, even though a host of models have been developed. The object of this review is to describe several of the most relevant mathematical models of the cardiovascular system: the physiological features of circulatory dynamics are explained, and their mathematical formulations are compared. The focus is on the whole-body scale mathematical models that portray the subject’s responses to hypovolemic shock. The models contained in this review differ from one another, both in the mathematical methodology adopted and in the physiological or pathological aspects described. Each model, in fact, mimics different aspects of cardiocirculatory physiology and pathophysiology to varying degrees: some of these models are geared to better understand the mechanisms of vascular hemodynamics, whereas others focus more on disease states so as to develop therapeutic standards of care or to test novel approaches. We will elucidate key issues involved in the modeling of cardiovascular system and its control by reviewing seven of these models developed to address these specific purposes.

Cardiorespiratory monitoring equipment interferes with whole body impedance measurements

2005 ◽  
Vol 26 (2) ◽  
pp. S235-S240 ◽  
Author(s):  
Barbara E Lingwood ◽  
Kimble R Dunster ◽  
Leigh C Ward
Keyword(s):  
Whole Body ◽  
Monitoring Equipment ◽  
Impedance Measurements ◽  
Body Impedance

Comparison of segmental with whole-body impedance measurements in peritoneal dialysis patients

2008 ◽  
Vol 30 (7) ◽  
pp. 817-824 ◽  
Author(s):  
Lexa Nescolarde ◽  
Teresa Doñate ◽  
Antonio Piccoli ◽  
Javier Rosell
Keyword(s):  
Peritoneal Dialysis ◽  
Whole Body ◽  
Dialysis Patients ◽  
Impedance Measurements ◽  
Body Impedance

scholarly journals Evaluation of Position Resolution for a Prototype Whole-Body PET Detector Based on Suppressing Backgrounds by Compton Scattering

2018 ◽  
Vol 170 ◽  
pp. 09004
Author(s):  
Kento FUJIHARA ◽  
Yusaku EMOTO ◽  
Hiroshi ITO ◽  
Naomi KANEKO ◽  
Hideyuki KANEKO ◽  
...  
Keyword(s):  
Compton Scattering ◽  
Pure Water ◽  
High Growth ◽  
Whole Body ◽  
Bottom Surface ◽  
Measuring Instruments ◽  
Position Resolution ◽  
Prototype Detector ◽  
Single Emission ◽  
Scattering Events

Existing PET (Positron Emission Tomography) systems make clear images in demonstration (measuring small PET reagent in pure water), however images in real diagnosis become unclear. The authors suspected that this problem was caused by Compton scattering in a detector. When PET systems observe plural photomultiplier tube outputs, an original emission point is regarded as centroid of the outputs. However, even if plural emission in Compton scattering occur, these systems calculate original point in the same way as single emission. Therefore, the authors considered that rejecting Compton scattering events makes PET systems much better, and made prototype counter. Main components of the prototype counter are plate-like high-growth-rate (HGR) La-GPS scintillators and wavelength shifting fibers (WLSF). HGR crystals grow 10 times as fast as a mono-crystal (a normal mono-crystal grows at 2 – 3 mm an hour). Thus, it includes microbubble and its transparency get worth. Consequently, HGR crystals usually are not used in radiation measuring instruments. However, this time they are used on the purpose. Because of their low transparency, scintillation lights come out right above and right under of emission position. Therefore, Compton scattering events is rejected easily. The prototype detector has an effective area of 300 by 300 square mm. The detector consists of 24 layers. One layer consists of HGR La-GPS scintillator of 1 mm thickness. Top and bottom surface of scintillator were covered by dual sheets of WLSF with a diameter of 0.2 mm. Sheets of WLSF on top and bottom of the scintillator make a right angle with each other, and measure X- and Y-components. Z-component is measured by difference of WLSF outputs between top and bottom. If plural layers output signals, this counter regards the event as Compton scattering event, and reject the event. Even if only a layer output signals, the event is rejected when number output signals from WLSF is more than 1.5 times of single emission. Material cost of this system is, 0.2M$ for HGR La-GPS, 0.03M$ for WLSF, 0.03M$ for 600 units of 6 by 6 mm SiPM's, 0.12M$ for 12000 units of 1 by 1 mm SiPM's, and 0.09M$ for 1800 channel of signal readout circuits. Considering total cost, price of this PET will be set 1M$ or less. This idea was confirmed with numerical simulation and experimentation. In experimentation, position resolution in photoelectric absorption was 0.2 mm, and minimum distance that this detector could recognize plural emission in Compton scattering was 1 mm. In parallel, three kinds of model were made: a prototype detector, all the signals readout method, and resistance delay method. Simulation setting was 2 MBq/L in normal tissue and 10 MBq/L in cancer. As a result of simulation, a prototype detector identified 3 mm cancer, however the others made unclear image and was not able to identified cancer. That is to say, the prototype detector is able to reject Compton scattering events and inexpensive. Therefore, whole-body PET system with this detector must diagnose cancer with a diameter of 3 mm or more and be priced 1M$ or less

scholarly journals Increases in circulating megakaryocyte growth-promoting activity in the plasma of rats following whole body irradiation

Blood ◽  
1984 ◽  
Vol 63 (5) ◽  
pp. 1060-1066 ◽  
Author(s):  
M Miura ◽  
CW Jackson ◽  
SA Lyles
Keyword(s):  
Bone Marrow ◽  
Plasma Concentration ◽  
Bone Marrow Cells ◽  
Single Cells ◽  
Rat Plasma ◽  
Whole Body ◽  
Growth Promoting ◽  
Marrow Cells

Abstract To gain insight into the regulation of megakaryocyte precursors in vivo, we assayed (in vitro) megakaryocyte growth-promoting activity (Meg-GPA) in plasma of rats in which both marrow hypoplasia and thrombocytopenia had been induced by irradiation. Rats received whole body irradiation of 834 rad from a 137Cs source. Plasma was collected at intervals of hours to days, up through day 21 postirradiation, and was tested, at a concentration of 30%, for Meg-GPA on bone marrow cells cultured in 1.1% methylcellulose with 5 X 10(-5) M 2-mercaptoethanol. With normal rat plasma, no megakaryocyte colonies (defined as greater than or equal to 4 megakaryocytes) were seen and only a few single megakaryocytes and clusters (defined as 2 or 3 megakaryocytes) were formed. Two peaks of plasma Meg-GPA were observed after irradiation. The first appeared at 12 hr, before any decrease in marrow megakaryocyte concentration or platelet count. The second occurred on days 10–14 after irradiation, after the nadir in megakaryocyte concentration and while platelet counts were at their lowest levels. A dose-response study of plasma concentration and megakaryocyte growth, using plasma collected 11 days postirradiation, demonstrated that patterns of megakaryocyte growth were related to plasma concentration; formation of single megakaryocytes was optimal over a range of 20%-30% plasma concentration, while cluster and colony formation were optimal at a plasma concentration of 30%. All forms of megakaryocyte growth were decreased with 40% plasma. There was a linear relationship between the number of bone marrow cells plated and growth of single cells, clusters, and colonies using a concentration of 30% plasma collected 11 days after irradiation. We conclude that irradiation causes time- related increases in circulating megakaryocyte growth-promoting activity. We suggest that the irradiated rat is a good model for studying the relationships between Meg-GPA and megakaryocyte and platelet concentration in vivo.

scholarly journals Homogentisic acid-derived pigment as a biocompatible label for optoacoustic imaging of macrophages

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Ina Weidenfeld ◽  
Christian Zakian ◽  
Peter Duewell ◽  
Andriy Chmyrov ◽  
Uwe Klemm ◽  
...  
Keyword(s):  
Single Cells ◽  
Cell Types ◽  
Homogentisic Acid ◽  
Tissue Imaging ◽  
Whole Body ◽  
Whole Body Imaging ◽  
Optoacoustic Imaging ◽  
Pigment Formation ◽  
Functionally Diverse

Abstract Macrophages are one of the most functionally-diverse cell types with roles in innate immunity, homeostasis and disease making them attractive targets for diagnostics and therapy. Photo- or optoacoustics could provide non-invasive, deep tissue imaging with high resolution and allow to visualize the spatiotemporal distribution of macrophages in vivo. However, present macrophage labels focus on synthetic nanomaterials, frequently limiting their ability to combine both host cell viability and functionality with strong signal generation. Here, we present a homogentisic acid-derived pigment (HDP) for biocompatible intracellular labeling of macrophages with strong optoacoustic contrast efficient enough to resolve single cells against a strong blood background. We study pigment formation during macrophage differentiation and activation, and utilize this labeling method to track migration of pro-inflammatory macrophages in vivo with whole-body imaging. We expand the sparse palette of macrophage labels for in vivo optoacoustic imaging and facilitate research on macrophage functionality and behavior.

Capillary Force Driven Single-Cell Spiking Apparatus for Studying Circulating Tumor Cells

2018 ◽  
Author(s):  
Jacob Amontree ◽  
Kangfu Chen ◽  
Jose Varillas ◽  
Z. Hugh Fan
Keyword(s):  
Single Cell ◽  
Tumor Cells ◽  
Circulating Tumor Cells ◽  
Single Cells ◽  
Lymphoblastic Leukemia ◽  
Surface Membrane ◽  
Critical Element ◽  
Cell Capture ◽  
Biomedical Sciences ◽  
Low Concentrations

The characterization of single cells within heterogeneous populations has great impact on both biomedical sciences and cancer research. By investigating cellular compositions on a broad scale, pertinent outliers may be lost in the sample set. Alternatively, an investigation focused on the behavior of specific cells, such as circulating tumor cells (CTCs), will reveal genetic biomarkers or phenotypic characteristics associated with cancer and metastasis. On average, CTC concentration in peripheral blood is extremely low, as few as one to two per billion of healthy blood cells. Consequently, the critical element lacking in many methods of CTC detection is accurate cell capture efficiency at low concentrations. To simulate CTC isolation, researchers usually spike small amounts of tumor cells to healthy blood for separation. However, spiking tumor cells at extremely low concentrations is challenging in a standard laboratory setting. We report our study on an innovative apparatus and method designed for low-cost, precise, and replicable single-cell spiking (SCS). Our SCS method operates solely from capillary aspiration without the reliance on external laboratory equipment. To ensure that our method does not affect the viability of each cell, we investigated the effects of surface membrane tensions induced by aspiration. Finally, we performed affinity-based CTC isolation using human acute lymphoblastic leukemia cells (CCRF-CEM) spiked into healthy whole blood with the SCS technique. The results of the isolation experiments demonstrate the reliability of our method in generating low-concentration cell samples.

scholarly journals Mitochondrial Correlation Microscopy and Nanolaser Spectroscopy — New Tools for Biophotonic Detection of Cancer in Single Cells

2005 ◽  
Vol 4 (6) ◽  
pp. 585-592 ◽  
Author(s):  
Paul L. Gourley ◽  
Judy K. Hendricks ◽  
Anthony E. McDonald ◽  
R. Guild Copeland ◽  
Keith E. Barrett ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Tumor Cells ◽  
High Throughput Screening ◽  
Laser Scanning ◽  
Spatial Organization ◽  
Early Stage ◽  
Single Cells ◽  
Normal Liver ◽  
Diagnosis And Treatment ◽  
Optical Methods

Currently, pathologists rely on labor-intensive microscopic examination of tumor cells using century-old staining methods that can give false readings. Emerging BioMicroNano-technologies have the potential to provide accurate, realtime, high-throughput screening of tumor cells without the need for time-consuming sample preparation. These rapid, nanooptical techniques may play an important role in advancing early detection, diagnosis, and treatment of disease. In this report, we show that laser scanning confocal microscopy can be used to identify a previously unknown property of certain cancer cells that distinguishes them, with single-cell resolution, from closely related normal cells. This property is the correlation of light scattering and the spatial organization of mitochondria. In normal liver cells, mitochondria are highly organized within the cytoplasm and highly scattering, yielding a highly correlated signal. In cancer cells, mitochondria are more chaotically organized and poorly scattering. These differences correlate with important bioenergetic disturbances that are hallmarks of many types of cancer. In addition, we review recent work that exploits the new technology of nanolaser spectroscopy using the biocavity laser to characterize the unique spectral signatures of normal and transformed cells. These optical methods represent powerful new tools that hold promise for detecting cancer at an early stage and may help to limit delays in diagnosis and treatment.

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