Anthropogammamètre (Wohle Body Counter) de Genève. II. Etalonnage pour le potassium naturel et variation de la teneur en potassium naturel en fonction du poids du sujet

Wenger, Pierre; Soucas, K.

doi:10.1002/hlca.19640470405

Cited by 6 publications

(6 citation statements)

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“…The calculated TBK content represents the BCM from which the lean body mass (LBM) (LBMTBK) can be extrapolated. This technique in humans, at our institution, has an accuracy of 5% and a precision of 2% 19 . Others reported a variability of potassium‐40 counting in an anthropometric phantom <5% and in humans around 5% 20 …”

Section: Methodsmentioning

confidence: 61%

“…The gamma photons emitted by the subject interacted with the crystal, sending an output signal to the spectrum analyzer. To minimized background interference, the subject and the detector were placed in a special room surrounded by thick steel walls 19 . The natural potassium‐40 isotope exists at a known and constant natural abundance of 0.0012%.…”

Section: Methodsmentioning

confidence: 99%

“…To minimized background interference, the subject and the detector were placed in a special room surrounded by thick steel walls. 19 The natural potassium-40 isotope exists at a known and constant natural abundance of 0.0012%. It was measured by counting the total pulses recorded in the channels of the photo peak of this isotope for 30 minutes.…”

Section: Body Cell Massmentioning

confidence: 99%

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Total Body Mass, Fat Mass, Fat‐Free Mass, and Skeletal Muscle in Older People: Cross‐Sectional Differences in 60‐Year‐Old Persons

Kyle

Genton

Hans

et al. 2001

J American Geriatrics Society

157

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OBJECTIVES:To evaluate body composition parameters, including fat-free mass (FFM), appendicular skeletal muscle mass (ASMM), relative skeletal muscle mass (RSM) index, body cell mass (BCM), BCM index, total body potassium (TBK), fat mass, percentage fat mass (FM), and their differences between age groups and to evaluate the frequency of sarcopenia in healthy older subjects DESIGN: Cross-sectional, nonrandomized study. SETTING: Outpatient clinic. PARTICIPANTS: Ninety-one healthy men and 100 healthy women age 60 and older. MEASUREMENTS: FFM, ASMM, FM, and percentage fat mass by whole-body dual-energy x-ray absorptiometry; TBK, BCM, and TBK/FFM ratio by whole body potassium-40 counter. RESULTS: All lean body mass parameters were significantly ( P Ͻ .05) lower in subjects age 80 and older than in those age 70 to 79, except ASMM in women. Mean FFM was 4.2 kg (7.3%) lower in men age 80 and older than in those younger than 70 and 2.9 kg (6.8%) lower in women age 80 and older than in those younger than 70. The skeletal muscle mass, reflected by ASMM, decreased more than FFM. This suggests that nonskeletal muscle mass is proportionally preserved during aging. Forty-five percent of men and 30% of women were sarcopenic by definition of BCM index and 11.0% of men and women by definition of RSM index. CONCLUSIONS: Significant age-related differences exist in body composition of older men and women between age 60 and 95. The greater decrease in TBK and BCM than the decrease in FFM and skeletal muscle mass suggests changing composition of FFM with age. Lack of agreement between two independent sarcopenia indexes suggests that further refinement in the definition of a sarcopenia index is necessary.

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Section: Methodsmentioning

confidence: 61%

Section: Methodsmentioning

confidence: 99%

Section: Body Cell Massmentioning

confidence: 99%

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Total Body Mass, Fat Mass, Fat‐Free Mass, and Skeletal Muscle in Older People: Cross‐Sectional Differences in 60‐Year‐Old Persons

Kyle

Genton

Hans

et al. 2001

J American Geriatrics Society

157

View full text Add to dashboard Cite

show abstract

“…It was measured by counting the total pulses recorded in the channels of the photo peak of this isotope for 30 min. This technique in humans, at our institution, has an accuracy of 5% and a precision of 2% (Wenger & Soucas, 1964). Others reported a variability of potassium-40 counting in an anthropometric phantom is b 5% and in humans around 5% (Lukaski et al, 1981).…”

Section: Body Composition Measurementsmentioning

confidence: 62%

Age-related differences in fat-free mass, skeletal muscle, body cell mass and fat mass between 18 and 94 years

et al. 2001

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Objective: To determine (1) lean and fat body compartments, re¯ected by fat-free mass (FFM), appendicular skeletal muscle mass (ASMM), body cell mass (BCM), total body potassium (TBK), fat mass and percentage fat mass, and their differences between age groups in healthy, physically active subjects from 18 to 94 y of age; and (2) if the rate of decrease in any one of the parameters by age might be accelerated compared to others. Methods: A total of 433 healthy ambulatory Caucasians (253 men and 180 women) aged 18 ± 94 y were measured by dual-energy X-ray absorptiometry (DXA) and whole body scintillation counter (TBK counter) using a large sodium iodide crystal (203 mm diameter). Results: The ASMM change (716.4 and 712.3% in men and women, respectively) in b 75 y-old compared to 18 to 34-y-old subjects was greater than the FFM change (711.8 and 79.7% in men and women, respectively) and this suggests that skeletal muscle mass decrease in older subjects was proportionally greater than non-skeletal muscle mass. BCM (725.1 and 723.2% in men and women, respectively) and TBK differences were greater than the differences in FFM or ASMM suggesting altered composition of FFM in older subjects. Women had lower peak FFM, ASMM, BCM and TBK than men. Conclusions: The decline in FFM, ASMM, BCM and TBK is accelerated in men and women after 60 y of age and FFM, ASMM, BCM and TBK are signi®cantly lower than in younger subjects. Fat mass continued to increase until around 75 y. Sponsorship: Foundation Nutrition 2000Plus, Geneva, Switzerland. Descriptors: dual energy X-ray absorptiometry (DXA); total body potassium (TBK); fat-free mass; appendicular skeletal muscle mass (ASMM); body cell mass (BCM); fat mass.

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“…The drug was administered with 150 ml of water. Lean body weight was determined with a whole body counter (Wenger & Soucas, 1964), by measuring the radioactivity due to the natural abundance of radioactive potassium [40K]. The assumption made is that potassium content per unit of lean body weight is constant.…”

Section: Protocolmentioning

confidence: 99%

Pharmacokinetics of theophylline: a dose‐range study.

Rovei¹,

Chanoine²,

Benedetti³

1982

Brit J Clinical Pharma

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1 Pharmacokinetics of theophylline were investigated in a group of healthy adult volunteers (non smokers and on xanthine-free diet) following single oral administration of 125, 250, 375 and 500 mg doses as tablets (Theodel(®). 2 Absorption of theophylline was rapid and followed first-order kinetics. Plasma curves were fitted according to a one compartment open model.3 There was a linear relationship (P < 0M.0)) between plasma Cmax or AUC, values and the administered dose. The analysis of variance showed that the pharmacokinetic parameters of theophylline (t,, abs, tmai, t. 3,, CL, CLR, Vd and F) were not modified at any dose.4 Absorption of the drug was complete since the recovery in urine of theophylline (13.7 to 16.8% of the dose) and its major metabolites, 1,3-dimethyluric acid (35 to 42%), 1-methyluric acid (21.3 to 26.7%) and 3-methylxanthine (11.5 to 13.7%), accounted for the administered dose. Some impairment of demethylation to 3-methylxanthine was observed in two subjects, however the percentage of theophylline and its major metabolites excreted in urine was constant for all the four doses. 5 On the basis of these results, after single oral administration, elimination of theophylline followed first-order kinetics in the range of doses investigated (1.62 to 10.42 mg/kg).

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Anthropogammamètre (Wohle Body Counter) de Genève. II. Etalonnage pour le potassium naturel et variation de la teneur en potassium naturel en fonction du poids du sujet

Abstract: The whole body counter of Geneva has been calibrated for potassium measurements by using a 42K standard solution and natural potassium.

Cited by 6 publications

References 1 publication

Total Body Mass, Fat Mass, Fat‐Free Mass, and Skeletal Muscle in Older People: Cross‐Sectional Differences in 60‐Year‐Old Persons

Total Body Mass, Fat Mass, Fat‐Free Mass, and Skeletal Muscle in Older People: Cross‐Sectional Differences in 60‐Year‐Old Persons

Age-related differences in fat-free mass, skeletal muscle, body cell mass and fat mass between 18 and 94 years

Pharmacokinetics of theophylline: a dose‐range study.

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