scholarly journals Experimental Evaluation of 65Zn Decorporation Kinetics Following Rapid and Delayed Zn-DTPA Interventions in Rats. Biphasic Compartmental and Square-Root Law Mathematical Modeling

Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1830
Author(s):  
Victor Voicu ◽  
Marilena Jiquidi ◽  
Constantin Mircioiu ◽  
Roxana Sandulovici ◽  
Adrian Nicolescu
Keyword(s):  
Single Dose ◽  
Term Treatment ◽  
Male Rats ◽  
Whole Body ◽  
Square Root ◽  
Living Body ◽  
Long Term Treatment ◽  
Body Counting ◽  
Finite Medium ◽  
Whole Body Counting

The decorporation kinetics of internal radionuclide contamination is a long-term treatment raising modeling, planning, and managing problems, especially in the case of late intervention when the radiotoxic penetrated the deep compartments. The decorporation effectiveness of the highly radiotoxic 65ZnCl2 by Zn-DTPA (dosed at 3.32 mg and 5 mg/0.25 mL/100 g body weight) was investigated in Wistar male rats over a ten-day period under various treatments (i.e., as a single dose before contamination; as a single dose before and 24 h after contamination; and as daily administrations for five consecutive days starting on day 12 after contamination). The radioactivity was measured using the whole-body counting method. Mono- and bi-compartmental decorporation kinetics models proved applicable in the case of a rapid intervention. It was found that a diffusion model of the radionuclide from tissues to blood better describes the decorporation kinetics after more than ten days post treatment, and the process has been mathematically modeled as a diffusion from an infinite reservoir to a semi-finite medium. The mathematical solution led to a square-root law for describing the 65Zn decorporation. This law predicts a slower release than exponential or multiexponential equations, and could better explain the very long persistence of radionuclides in the living body. Splitting data and modeling in two steps allows a better understanding, description and prediction of the evolution of contamination, a separate approach to the treatment schemes of acute and chronic contamination.

Studies of Calcium Absorption in Man Using a CD-2 Whole-Body Counter

1977 ◽  
Vol 16 (04) ◽  
pp. 163-167
Author(s):  
K. Bakos ◽  
Věra Wernischová
Keyword(s):  
Calcium Absorption ◽  
Whole Body ◽  
Control Group ◽  
Absorption Process ◽  
Whole Body Counter ◽  
Absorption Studies ◽  
Body Counting ◽  
Calcium Load ◽  
Calcium Malabsorption ◽  
Whole Body Counting

SummaryWhole-body counting makes an important contribution of radioisotope techniques to ȁEin vivo“ absorption studies, in comparison with other methods. In a large number of subjects, the method was tested for its usefulness in the diagnosis of calcium malabsorption. The effects of drugs, of the calcium load in the gut and of the whole-body content of calcium on the absorption process were studied in a control group.

A Modified Chair Geometry for Whole Body Counting

1976 ◽  
Vol 15 (05) ◽  
pp. 246-247
Author(s):  
S. C. Jain ◽  
G. C. Bhola ◽  
A. Nagaratnam ◽  
M. M. Gupta
Keyword(s):  
Marked Improvement ◽  
Point Of View ◽  
Whole Body ◽  
Spatial Response ◽  
Body Counting ◽  
The Subject ◽  
Whole Body Counting ◽  
The Buddha

SummaryIn the Marinelli chair, a geometry widely used in whole body counting, the lower part of the leg is seen quite inefficiently by the detector. The present paper describes an attempt to modify the standard chair geometry to minimise this limitation. The subject sits crossed-legged in the “Buddha Posture” in the standard chair. Studies with humanoid phantoms and a volunteer sitting in the Buddha posture show that this modification brings marked improvement over the Marinelli chair both from the point of view of sensitivity and uniformity of spatial response.

scholarly journals Bilateral Renal Colic as an Initial Presentation of Erdheim-Chester Disease

2019 ◽  
Vol 2019 ◽  
pp. 1-4
Author(s):  
Julien Sarkis ◽  
Fady Haddad ◽  
Sarah Nasr ◽  
Elie Hanna ◽  
Ahmad Mroueh ◽  
...  
Keyword(s):  
Renal Colic ◽  
Kidney Injury ◽  
Term Treatment ◽  
Whole Body ◽  
Ct Guided ◽  
Erdheim Chester Disease ◽  
Positron Emission ◽  
Long Term Treatment ◽  
Erdheim Chester ◽  
Chester Disease

Erdheim-Chester disease (ECD) is a rare non-Langerhans cells histiocytosis characterized by multiorgan involvement, with renal-ECD documented in over one-third of patients. Renal disease is generally asymptomatic, rarely causing hydronephrosis and kidney impairment. In addition, the diverse clinical picture of Erdheim-Chester disease arises slowly with sequential manifestations. We present a rare case of a 75-year-old woman on long-term treatment for panhypopituitarism and steroid therapy for vasculitis, presenting to the emergency department with bilateral renal colic and acute kidney injury. Abdominopelvic CT scan revealed renal infiltration with signs of retroperitoneal fibrosis and hydronephrosis. Kidney CT-guided biopsy and 18-fluorodeoxyglucose (FDG) positron emission tomography whole body scan as well as the history of hypopituitarism and vasculitis confirmed the diagnosis of Erdheim-Chester disease. Proper therapy with interferon-α was started. This case describes the multifaced manifestation of this disease and the difficulty to establish the diagnosis, as well as the pivotal role that a urologist can play in its management.

Body potassium by four-pi 40K counting: an anthropometric correction

1984 ◽  
Vol 246 (2) ◽  
pp. F234-F239 ◽  
Author(s):  
R. N. Pierson ◽  
J. Wang ◽  
J. C. Thornton ◽  
T. B. Van Itallie ◽  
E. W. Colt
Keyword(s):  
Adipose Tissue ◽  
Single Crystal ◽  
Covariance Analysis ◽  
Whole Body ◽  
Exchangeable Sodium ◽  
Independent Evidence ◽  
Body Counting ◽  
Whole Body Counting

Four-pi whole body counting for the 1.46 meV photon of 40K has apparent advantages over single-crystal or two-pi counters in efficiency and in subject geometry independence. However, our studies of obese populations have disclosed a systematic undermeasurement of 40K, suggesting that nonhomogeneous K distribution results in systematic undercounting of 40K. In the current study 42K, emitting a 1.52 meV photon, was used in 109 volunteers ranging from 50 to 181 kg, and multiregression covariance analysis was applied to develop correction formulas based on anthropometrics. These corrections quantitatively account for the unappreciated loss of 40K and 42K photons in annular adipose tissue that surrounds the lean body, in which most K+ is concentrated. The correction ranges from 1 to 28% and is a linear (although different) function of weight in both sexes. Thus corrected, body potassium measurements, taken in conjunction with exchangeable sodium and water measurements, provide estimates for whole body osmolality that match measured serum values. Such a quantitative accounting for previously "lost" cation in 58 subjects provides independent evidence for the appropriateness and accuracy of the correction. With this correction, body potassium was recalculated in the 1,492 adult members of a previously reported group of 3,083 subjects.

Whole Body Counting of Vitamin B12 58Co Absorption Supplemented by Profile Scanning

1970 ◽  
Vol 5 (4) ◽  
pp. 261-264
Author(s):  
N. D. C. Finlayson ◽  
J. D. Simpson ◽  
D. J. C. Shearman
Keyword(s):  
Vitamin B12 ◽  
Whole Body ◽  
Body Counting ◽  
Whole Body Counting

scholarly journals Brief Note: A Note Concerning the "100 Per Cent Value" in Iron Absorption Studies by Whole Body Counting

Blood ◽  
1964 ◽  
Vol 23 (6) ◽  
pp. 757-761 ◽  
Author(s):  
LEWIS M. SCHIFFER ◽  
D. C. PRICE ◽  
J. CUTTNER ◽  
S. H. COHN ◽  
EUGENE P. CRONKITE
Keyword(s):  
Iron Absorption ◽  
Whole Body ◽  
Body Counter ◽  
Whole Body Counter ◽  
Absorption Studies ◽  
Body Counting ◽  
Whole Body Counting ◽  
Body Count

Abstract The 4-hour whole body count is found to be clinically valid as a "100 per cent value" in iron absorption studies performed with a whole body counter. Measurement of iron absorption can be made 2 weeks after ingestion of radioiron, but not prior to this period.

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