Effect of acute hyaluronidase treatment of the glycocalyx on tracer-based whole body vascular volume estimates in mice

2013 ◽  
Vol 114 (9) ◽  
pp. 1132-1140 ◽  
Author(s):  
Jurgen W. G. E. VanTeeffelen ◽  
Judith Brands ◽  
Ben J. A. Janssen ◽  
Hans Vink
Keyword(s):  
Barrier Properties ◽  
Distribution Volume ◽  
The Body ◽  
Endothelial Glycocalyx ◽  
Whole Body ◽  
Differential Distribution ◽  
Vascular Volume ◽  
Body Distribution ◽  
Volume Measurements ◽  
Tracer Dilution

The endothelial glycocalyx forms a hyaluronan-containing interface between the flowing blood and the endothelium throughout the body. By comparing the systemic distribution of a small glycocalyx-accessible tracer vs. a large circulating plasma tracer, the size-selective barrier properties of the glycocalyx have recently been utilized to estimate whole body glycocalyx volumes in humans and animals, but a comprehensive validation of this approach has been lacking at the moment. In the present study, we compared, in anesthetized, ventilated C57Bl/6 mice, the whole body distribution of small (40 kDa) dextrans (Texas Red labeled; Dex40) vs. that of intermediate (70 kDa) and large (500 kDa) dextrans (both FITC labeled; Dex70 and Dex500, respectively) using tracer dilution and vs. that of circulating plasma, as derived from the dilution of fluorescein-labeled red blood cells and large-vessel hematocrit. The contribution of the glycocalyx was evaluated by intravenous infusion of a bolus of the enzyme hyaluronidase. In saline-treated control mice, distribution volume (in ml) differed between tracers ( P < 0.05; ANOVA) in the following order: Dex40 (0.97 ± 0.04) > Dex70 (0.90 ± 0.04) > Dex500 (0.81 ± 0.10) > plasma (0.71 ± 0.02), resulting in an inaccessible vascular volume, i.e., compared with the distribution volume of Dex40, of 0.03 ± 0.01, 0.15 ± 0.04, and 0.31 ± 0.05 ml for Dex70, Dex500, and plasma, respectively. In hyaluronidase-treated mice, Dex70 and Dex40 volumes were not different from each other, and inaccessible vascular volumes for Dex500 (0.03 ± 0.03) and plasma (0.14 ± 0.05) were smaller ( P < 0.05) than those in control animals. Clearance of Dex70 and Dex500 from the circulation was enhanced ( P < 0.05) in hyaluronidase-treated vs. control mice. These results indicate that the glycocalyx contributes to size-dependent differences in whole body vascular distribution of plasma solutes in mice. Whole body vascular volume measurements based on the differential distribution of glycocalyx-selective tracers appear appropriate for the detection of generalized glycocalyx degradation in experimental animals and humans.

scholarly journals Gamma camera imaging for studying intestinal absorption and whole-body distribution of selenomethionine

2013 ◽  
Vol 111 (3) ◽  
pp. 547-553 ◽  
Author(s):  
Jan L. Madsen ◽  
Katarina Sjögreen-Gleisner ◽  
Dennis R. Elema ◽  
Lasse R. Søndergaard ◽  
Palle Rasmussen ◽  
...  
Keyword(s):  
Gamma Camera ◽  
The Body ◽  
Whole Body ◽  
Time Activity ◽  
Gamma Camera Imaging ◽  
Camera Imaging ◽  
Body Distribution ◽  
Body Retention ◽  
Faecal Samples ◽  
Predominant Form

Se metabolism in humans is not well characterised. Currently, the estimates of Se absorption, whole-body retention and excretion are being obtained from balance and tracer studies. In the present study, we used gamma camera imaging to evaluate the whole-body retention and distribution of radiolabelled selenomethionine (SeMet), the predominant form of Se present in foods. A total of eight healthy young men participated in the study. After consumption of a meal containing 4 MBq [75Se]l-SeMet ([75Se]SeMet), whole-body gamma camera scanning was performed for 45 min every hour over a 6 h period, every second hour for the next 18 h and once on each of the subsequent 6 d. Blood, urine and faecal samples were collected to determine the plasma content of [75Se]SeMet as well as its excretion in urine and faeces. Imaging showed that 87·9 (sd 3·3) % of the administered activity of [75Se]SeMet was retained within the body after 7 d. In contrast, the measured excretion in urine and faeces for the 7 d period was 8·2 (sd 1·1) % of the activity. Time–activity curves were generated for the whole body, stomach, liver, abdomen (other than the stomach and the liver), brain and femoral muscles. Gamma camera imaging allows for the assessment of the postprandial absorption of SeMet. This technique may also permit concurrent studies of organ turnover of SeMet.

MO599COMPARISON OF TOTAL BODY WATER MEASURED BY BIOIMPEDANCE SPECTROSCOPY TO UREA DISTRIBUTION VOLUME ESTIMATED FROM UREA KINETIC MODELING IN HEMODIALYSIS PATIENTS

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Ariella Mermelstein ◽  
Ulrich Moissl ◽  
Bernard Canaud ◽  
Jeroen Kooman ◽  
Rachel Lasky ◽  
...  
Keyword(s):  
Body Composition ◽  
Kinetic Modeling ◽  
Total Body Water ◽  
Distribution Volume ◽  
Body Water ◽  
The Body ◽  
Whole Body ◽  
Tissue Mass ◽  
Total Body ◽  
Urea Distribution Volume

Abstract Background and Aims Monitoring of fluid, body composition and nutritional changes is important in clinical nephrology. The Body Composition Monitor (BCM; Fresenius Medical Care, Bad Homburg, Germany) measures whole-body bioimpedance and determines extracellular and intracellular resistance by using the Cole-model to estimate total body water (TBW-BCM) and its partition into extracellular and intracellular water. Both can then be used to define body composition and separate body weight into lean tissue mass, adipose tissue mass, and fluid overload. Urea kinetic modeling (UKM) allows the estimation of dialysis dose (double-pooled Kt/V), urea distribution volume (V-UKM) and dietary protein intake. We studied the bias between estimated V-UKM to anthropometric and measured TBW-BCM (Vant, TBW-BCM). Method Pre-hemodialysis (HD), electrodes for the BCM assessments were placed on the non-arteriovenous access arm and ipsilateral leg, respectively, with the patient in a supine position. Vant was calculated using the Watson equation. In addition to these assessments we entered the specified values from the most recent urea kinetic modeling (UKM) treatment into the online solute-solver calculator (http://ureakinetics.org). We chose a baseline ratio of modeled/anthropometric volume of 0.6 to 1.3 L to exclude values with data entry errors and/or UKM sampling errors. We calculated the post HD TBW-BCM by subtracting the intradialytic weight loss and adjusted these estimates by the differences in post HD weight between sessions to make both estimates comparable. We depicted the comparison between the estimated V-UKM versus the TBW-BCM in a scatter- and Bland-Altman (BA) plot (Figure). For the purpose of error investigation we studied the computed bias (V-UKM minus TBW-BCM) as a function of body mass index (BMI) and stray capacitance (td) in a BA plot. We then calculated the difference between Vant and V-UKM and illustrated the comparison in a scatter and BA plot. Results In a cross-sectional design, we studied 161 stable prevalent HD patients (61.3±14.7 years, 98 (60.9%) males, height of 167.5±10.7 cm) prior to their treatment. The regression plot showed slight agreement (R2= 0.69) and the Bland-Altman plot no systematic trends or proportional error in the main analysis (Figure 1a and b). Neither BMI or td explained bias and variance in the bias between both estimates. Vant and V-UKM plots showed agreement (R2 of 0.68) with a mean bias of -2.3±5.1 and no proportional error. Conclusion Both TBW-BCM and the V-UKM as the “bronze standard” of TBW estimation seemed to agree reasonably well. Neither body composition measurement or kinetic modeling approach showed any significant influence on the accuracy and precision of the estimate. According to BCM availability, estimated V-UKM or measured TBW-BCM could be used alternatively in practice to support clinical decision when pharmacokinetic considerations are concerned.

A Simple and Inexpensive Clinical Whole Body Counter

1976 ◽  
Vol 15 (05) ◽  
pp. 248-253
Author(s):  
A. K. Basu ◽  
S. K. Guha ◽  
B. N. Tandon ◽  
M. M. Gupta ◽  
M. ML. Rehani
Keyword(s):  
The Body ◽  
Whole Body ◽  
Vitro Assay ◽  
Body Counter ◽  
Optimum Parameters ◽  
Whole Body Counter ◽  
Single Detector ◽  
Background Index ◽  
Iodide Crystal

SummaryThe conventional radioisotope scanner has been used as a whole body counter. The background index of the system is 10.9 counts per minute per ml of sodium iodide crystal. The sensitivity and derived sensitivity parameters have been evaluated and found to be suitable for clinical studies. The optimum parameters for a single detector at two positions above the lying subject have been obtained. It has been found that for the case of 131I measurement it is possible to assay a source located at any point in the body with coefficient of variation less than 5%. To add to the versatility, a fixed geometry for in-vitro counting of large samples has been obtained. The retention values obtained by the whole body counter have been found to correlate with those obtained by in-vitro assay of urine and stool after intravenous administration of 51Cr-albumin.

Toxicology

2017 ◽  
Author(s):  
Robert Laumbach ◽  
Michael Gochfeld
Keyword(s):  
Molecular Mechanisms ◽  
Molecular Targets ◽  
Toxicity Testing ◽  
The Body ◽  
Toxic Substances ◽  
Basic Principles ◽  
Practical Applications ◽  
Mechanisms Of Toxicity ◽  
Body Distribution ◽  
Threshold Doses

This chapter describes the basic principles of toxicology and their application to occupational and environmental health. Topics covered include pathways that toxic substances may take from sources in the environment to molecular targets in the cells of the body where toxic effects occur. These pathways include routes of exposure, absorption into the body, distribution to organs and tissues, metabolism, storage, and excretion. The various types of toxicological endpoints are discussed, along with the concepts of dose-response relationships, threshold doses, and the basis of interindividual differences and interspecies differences in response to exposure to toxic substances. The diversity of cellular and molecular mechanisms of toxicity, including enzyme induction and inhibition, oxidative stress, mutagenesis, carcinogenesis, and teratogenesis, are discussed and the chapter concludes with examples of practical applications in clinical evaluation and in toxicity testing.

Visualization of Invasion into the Body and Internal Diffusion of Nanoparticles

2008 ◽  
Vol 396-398 ◽  
pp. 569-572
Author(s):  
Fumio Watari ◽  
Shigeaki Abe ◽  
I.D. Rosca ◽  
Atsuro Yokoyama ◽  
Motohiro Uo ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Fluorescent Microscopy ◽  
The Body ◽  
Internal Diffusion ◽  
Whole Body ◽  
X Ray ◽  
Body Level ◽  
Organ Level ◽  
Level 2 ◽  
Internal Body

Nanoparticles may invade directly into the internal body through the respiratory or digestive system and diffuse inside body. The behavior of nanoparticles in the internal body is also essential to comprehend for the realization of DDS. Thus it is necessary to reveal the internal dynamics for the proper treatments and biomedical applications of nanoparticles. In the present study the plural methods with different principles such as X-ray scanning analytical microscope (XSAM), MRI and Fluorescent microscopy were applied to enable the observation of the internal diffusion of micro/nanoparticles in the (1) whole body level, (2) inner organ level and (3) tissue and intracellular level. Chemical analysis was also done by ICP-AES for organs and compared with the results of XSAM mapping.

scholarly journals Making the choice between bioelectrical impedance measures for body hydration status assessment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dmitry M. Davydov ◽  
Andrey Boev ◽  
Stas Gorbunov
Keyword(s):  
Body Schema ◽  
Bioelectrical Impedance ◽  
Information Criterion ◽  
The Body ◽  
Whole Body ◽  
Hydration Status ◽  
Status Assessment ◽  
Best Fitting ◽  
Body Compartments ◽  
Fitting In

AbstractSituational or persistent body fluid deficit (i.e., de- or hypo-hydration) is considered a significant health risk factor. Bioimpedance analysis (BIA) has been suggested as an alternative to less reliable subjective and biochemical indicators of hydration status. The present study aimed to compare various BIA models in the prediction of direct measures of body compartments associated with hydration/osmolality. Fish (n = 20) was selected as a biological model for physicochemically measuring proximate body compartments associated with hydration such as water, dissolved proteins, and non-osseous minerals as the references or criterion points. Whole-body and segmental/local impedance measures were used to investigate a pool of BIA models, which were compared by Akaike Information Criterion in their ability to accurately predict the body components. Statistical models showed that ‘volumetric-based’ BIA measures obtained in parallel, such as distance2/Rp, could be the best approach in predicting percent of body moisture, proteins, and minerals in the whole-body schema. However, serially-obtained BIA measures, such as the ratio of the reactance to resistance and the resistance adjusted for distance between electrodes, were the best fitting in predicting the compartments in the segmental schema. Validity of these results should be confirmed on humans before implementation in practice.

scholarly journals Integumentary Colour Allocation in the Stork Family (Ciconiidae) Reveals Short-Range Visual Cues for Species Recognition

Birds ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 138-146
Author(s):  
Eduardo J. Rodríguez-Rodríguez ◽  
Juan J. Negro
Keyword(s):  
Short Range ◽  
Visual Cues ◽  
Species Recognition ◽  
The Body ◽  
Whole Body ◽  
Divergent Evolution ◽  
Black And White ◽  
Extant Species ◽  
Chromatic Spectrum ◽  
Mixed Species Flocks

The family Ciconiidae comprises 19 extant species which are highly social when nesting and foraging. All species share similar morphotypes, with long necks, a bill, and legs, and are mostly coloured in the achromatic spectrum (white, black, black, and white, or shades of grey). Storks may have, however, brightly coloured integumentary areas in, for instance, the bill, legs, or the eyes. These chromatic patches are small in surface compared with the whole body. We have analyzed the conservatism degree of colouration in 10 body areas along an all-species stork phylogeny derived from BirdTRee using Geiger models. We obtained low conservatism in frontal areas (head and neck), contrasting with a high conservatism in the rest of the body. The frontal areas tend to concentrate the chromatic spectrum whereas the rear areas, much larger in surface, are basically achromatic. These results lead us to suggest that the divergent evolution of the colouration of frontal areas is related to species recognition through visual cue assessment in the short-range, when storks form mixed-species flocks in foraging or resting areas.

scholarly journals Human Biodistribution and Radiation Dosimetry of the P-Glycoprotein Radiotracer [11C]Metoclopramide

2021 ◽  
Author(s):  
Martin Bauer ◽  
Sandra Barna ◽  
Matthias Blaickner ◽  
Konstantin Prosenz ◽  
Karsten Bamminger ◽  
...  
Keyword(s):  
Urinary Bladder ◽  
Healthy Volunteers ◽  
Effective Dose ◽  
Left Kidney ◽  
Whole Body ◽  
Red Bone Marrow ◽  
Body Distribution ◽  
P Glycoprotein ◽  
Pet Tracer ◽  
Male Subjects

Abstract Purpose To assess in healthy volunteers the whole-body distribution and dosimetry of [11C]metoclopramide, a new positron emission tomography (PET) tracer to measure P-glycoprotein activity at the blood-brain barrier. Procedures Ten healthy volunteers (five women, five men) were intravenously injected with 387 ± 49 MBq of [11C]metoclopramide after low dose CT scans and were then imaged by whole-body PET scans from head to upper thigh over approximately 70 min. Ten source organs (brain, thyroid gland, right lung, myocardium, liver, gall bladder, left kidney, red bone marrow, muscle and the contents of the urinary bladder) were manually delineated on whole-body images. Absorbed doses were calculated with QDOSE (ABX-CRO) using the integrated IDAC-Dose 2.1 module. Results The majority of the administered dose of [11C]metoclopramide was taken up into the liver followed by urinary excretion and, to a smaller extent, biliary excretion of radioactivity. The mean effective dose of [11C]metoclopramide was 1.69 ± 0.26 μSv/MBq for female subjects and 1.55 ± 0.07 μSv/MBq for male subjects. The two organs receiving the highest radiation doses were the urinary bladder (10.81 ± 0.23 μGy/MBq and 8.78 ± 0.89 μGy/MBq) and the liver (6.80 ± 0.78 μGy/MBq and 4.91 ± 0.74 μGy/MBq) for female and male subjects, respectively. Conclusions [11C]Metoclopramide showed predominantly renal excretion, and is safe and well tolerated in healthy adults. The effective dose of [11C]metoclopramide was comparable to other 11C-labeled PET tracers.

scholarly journals Comparison of superficial wound documentation using 2D forensic photography, 3D photogrammetry, Botscan© and VR with real-life examination

2021 ◽  
Vol 17 (3) ◽  
pp. 422-430
Author(s):  
Federico Massini ◽  
Lars Ebert ◽  
Garyfalia Ampanozi ◽  
Sabine Franckenberg ◽  
Lena Benz ◽  
...  
Keyword(s):  
Gold Standard ◽  
3D Visualization ◽  
Real Life ◽  
The Body ◽  
Whole Body ◽  
Forest Plot ◽  
Technical Documentation ◽  
Forensic Photography ◽  
Head Mounted Display ◽  
Significant Difference

AbstractEvidence acquisition, interpretation and preservation are essential parts of forensic case work that make a standardized documentation process fundamental. The most commonly used method for the documentation and interpretation of superficial wounds is a combination of two modalities: two-dimensional (2D) photography for evidence preservation and real-life examination for wound analysis. As technologies continue to develop, 2D photography is being enhanced with three-dimensional (3D) documentation technology. In our study, we compared the real-life examination of superficial wounds using four different technical documentation and visualization methods.To test the different methods, a mannequin was equipped with several injury stickers, and then the different methods were applied. A total of 42 artificial injury stickers were documented in regard to orientation, form, color, size, wound borders, wound corners and suspected mechanism of injury for the injury mechanism. As the gold standard, superficial wounds were visually examined by two board-certified forensic pathologists directly on the mannequin. These results were compared to an examination using standard 2D forensic photography; 2D photography using the multicamera system Botscan©, which included predefined viewing positions all around the body; and 3D photogrammetric reconstruction based on images visualized both on screen and in a virtual reality (VR) using a head-mounted display (HMD).The results of the gold standard examination showed that the two forensic pathologists had an inter-reader agreement ranging from 69% for the orientation and 11% for the size of the wounds. A substantial portion of the direct visual documentation showed only a partial overlap, especially for the items of size and color, thereby prohibiting the statistical comparison of these two items. A forest plot analysis of the remaining six items showed no significant difference between the methods. We found that among the forensic pathologists, there was high variability regarding the vocabulary used for the description of wound morphology, which complicated the exact comparison of the two documentations of the same wound.There were no significant differences for any of the four methods compared to the gold standard, thereby challenging the role of real-life examination and 2D photography as the most reliable documentation approaches. Further studies with real injuries are necessary to support our evaluation that technical examination methods involving multicamera systems and 3D visualization for whole-body examination might be a valid alternative in future forensic documentation.

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