The use of body hydrogen as an internal standard in the measurement of nitrogen in vivo by prompt neutron capture gamma-ray analysis

Vartsky, D.; Prestwich, W.V.; Thomas, Brian; Dabek, J. T.; Chettle, David R.; Fremlin, J. H.; Stammers, K.

doi:10.1007/bf02519790

Cited by 67 publications

(27 citation statements)

References 4 publications

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“…Total body protein: Total body protein was calculated from the direct measurement of total body nitrogen (TBN) by prompt in vivo neutron activation analysis (IVNAA) assuming that 1 g nitrogen is equivalent to 6.25 g protein (Vartsky et al 1979;Widdowson and Dickerson 1981). Subjects lay supine on a movable bed that was positioned to centre the trunk section in a collimated neutron beam measuring 40 cm × 20 cm at a bed level 35 cm above a 10 g 252 Cf neutron source.…”

Section: Methodsmentioning

confidence: 99%

Body composition in young adults with inborn errors of protein metabolism—A pilot study

Wilcox

Strauss

Francis

et al. 2004

J of Inher Metab Disea

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The natural history of inborn errors of protein metabolism and the long-term effects of prescribed semisynthetic therapeutic diets are largely unknown. We assessed body composition, measuring body-fat mass and distribution, fat-free mass, total body protein, total body potassium, bone density and skeletal muscle mass, in young adults (age > 18 years; 6 female, 5 male) with inborn errors of protein metabolism maintained on long-term low-protein diets, compared with controls. Female patients were significantly shorter (159.4 cm vs 169.2 cm, p = 0.013) and had higher BMI (25.3 vs 22.0 kg/m2, p < 0.05), abdominal to gluteal circumference ratio (0.84 vs 0.73, p = 0.011), percentage body fat (42.3% vs 29.5%, p < 0.005) and ratio of central to peripheral body fat (1.15 vs 0.86, p < 0.05) than controls. Male patients had lower height-adjusted total body bone mineral content (0.9 vs 1.02 g/m2, p < 0.04) and skeletal muscle mass (31.1 vs 36.3 kg, p < 0.04) than controls. Compared with controls, patients'nitrogen index was significantly lower (0.91 vs 1.03, p < 0.01), consistent with lower total body protein. Potassium index was significantly higher (121.2% vs 110.4%, p < 0.03), consistent with higher body cell mass, or intracellular water. Documentation of body composition in larger patient series is important to elucidate whether these results reflect increased risks (hence opportunities for prevention) of bone disease, metabolic syndrome and cardiovascular disease in this population.

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Section: Methodsmentioning

confidence: 99%

Body composition in young adults with inborn errors of protein metabolism—A pilot study

Wilcox

Strauss

Francis

et al. 2004

J of Inher Metab Disea

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“…It has been shown that this peak can serve as an internal reference standard for normalization of other peaks in the spectrum. 7 One equation that can be used to describe the relationship among total body carbon (TBC), total body hydrogen (TBH), and the ratio of counts in the 4.4 MeV peak to those in the 2.2 MeV peak is:…”

Section: Methodsmentioning

confidence: 99%

Total body fat mass based on the 4.4 MeV carbon peak in the in vivo prompt-gamma spectrum of the human body using241Am, Be neutrons

Ellis

Shypailo

1998

J Radioanal Nucl Chem

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The feasibility of measuring total body carbon (TBC) based on prompt-gamma activation analysis (PGAA) of the human body was examined. Preliminary analyzes for 33 healthy pre-menopausal women indicated a range of TBC values (7.1+4.4 kg) which translated to 17.1+6.5 kg body fat (27.9%+7.9% of body weight). An advantage of the PGAA measurement is that fat mass can be obtained simultaneous with that of total body protein mass, both indices serving as useful body composition markers of the nutritional status.

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“…This ratio is much less sensitive to variations in body size, neutron fluence and detector characteristics, which affect the signal from each element alone. It also permits the determination of TBN from partialbody irradiation (of the torso and thighs, thereby minimizing the radiation dose to radiosensitive tissues such as the eyes) assuming that hydrogen comprises one-tenth of body weight (Vartsky et al 1979). This requires correction since the proportion of body weight due to hydrogen has been estimated to vary from 9.5 to 10.8% in a large population of patients.…”

Section: Detectorsmentioning

confidence: 99%

Body Composition Analyzer Based on PGNAA Method

Panjeh¹,

Najafabadi²

2011

Radioisotopes - Applications in Physical Sciences

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The use of body hydrogen as an internal standard in the measurement of nitrogen in vivo by prompt neutron capture gamma-ray analysis

Cited by 67 publications

References 4 publications

Body composition in young adults with inborn errors of protein metabolism—A pilot study

Body composition in young adults with inborn errors of protein metabolism—A pilot study

Total body fat mass based on the 4.4 MeV carbon peak in the in vivo prompt-gamma spectrum of the human body using241Am, Be neutrons

Body Composition Analyzer Based on PGNAA Method

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