A Technique for measuring total-body nitrogen in clinical investigations using the 14N(n,2n) 13N reaction

Oxby, C B; Appleby, D.B.; Brooks, Kit; Burkinshaw, L.; Krupowicz, D. W.; McCarthy, I. D.; Oldroyd, B.; Ellis, Richard M.; Collins, John P.; Hill, Graham L.

doi:10.1016/0020-708x(78)90041-8

Cited by 42 publications

(11 citation statements)

References 9 publications

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“…The utility of 13 N-compounds as tracers in nuclear medicine [1,2] and environmental science [3] has recently been recognized. Several fundamental studies [4][5][6][7][8][9][10][11][12][13][14] have been reported on the chemical state of 13 N produced by the 14 N(n, 2«) 13 N reaction with 14 MeV-neutrons [4,5] and by the 12 C(<¿, η) 13 N [6~10] and the 16 Ο (ρ, α) 13 Ν reactions [11 -13] with cyclotron accelerated particles, in addition to the authors' preliminary study [14] on the 13 C(p, n) 13 N reaction by recoil protons produced in a nuclear reactor.…”

Section: Introductionmentioning

confidence: 99%

Effects of Irradiation Temperature and Irradiation Time on ¹³N-Compounds Produced by Recoil Protons in Benzene and Cyclohexane

Sensui¹,

Tomura²,

Shima³

et al. 1979

Radiochimica Acta

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The chemical state of nitrogen-13 produced by the 13 C(p, n) 13 Ν reaction by recoil protons in benzene and cyclohexane in the condensed phase was studied as a function of irradiation temperature in the range of -55° to +25°C, and of irradiation time from 5 to 20 min. The yields of HC' 3 N and C 6 H X C' 3 N showed remarkable phase dependence in both hydrocarbon media, i. e., the yield of HC 13 Ν increased and that of 13 N-nitrile decreased abruptly with an increase in irradiation temperature at the melting point. 13 N-ammonium and 13 N-amines like ethyl amine were produced in considerably greater amount in cyclohexane than in benzene, with a relatively small temperature dependence. These results suggest that hot 13 Ν forms C 13 Ν and 13 NH radicals as primary species, alongside with the hot insertion of 13 Ν into C-Η bonds. The degree of formation of C 13 N and 13 NH radicals seems to depend on the type of substrates, corresponding to the energies required to form these radicals by abstraction of a carbon or hydrogen atom. The data also suggest that C 13 N and 13 NH radicals undergo characteristic cage reactions depending on the phase.

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Section: Introductionmentioning

confidence: 99%

Effects of Irradiation Temperature and Irradiation Time on ¹³N-Compounds Produced by Recoil Protons in Benzene and Cyclohexane

Sensui¹,

Tomura²,

Shima³

et al. 1979

Radiochimica Acta

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“…and TBK in wasting disease a Forty-nine patients with organic bowel disease necessitating IVN,25 patients being acutely ill when studied by reason of fever, sepsis, inflammatory bowel disease, sepsis, or active tumors. Ninety-one patients with gastrointestinal disease, including 46 with inflammatory bowel disease and the majority of the remainder with cancer of the large bowel or stomach.…”

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confidence: 99%

Clinical Measurement of Body Composition Using In Vivo Neutron Activation Analysis

Beddoe

Hill

1985

J Parenter Enteral Nutr

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“…It is extremely unlikely that the precision for minerals was as high as 1.3 kg (twenty-seven times the measured value). It is also unlikely that the precision of TBN was four times the expected value; duplicate measurements of TBN in patients on successive days have been found to be as reproducible as measurements of phantoms (Oxby et al 1978). We conclude, therefore, that the most likely source of imprecision was the measurement of total body water.…”

Section: Discussionmentioning

confidence: 73%

“…Each patient was irradiated with fast neutrons to a dose equivalent of 5 mSv (500 mrem) in 40 s and then placed in a whole-body radiation counter for 30 min in order to measure the radioactivity induced in the body by the neutrons (Oxby et al 1978). The spectrum of emitted gamma rays was analysed to determine total body N, chlorine, potassium, phosphorus, calcium and sodium.…”

Section: In Vivo Neutron-activation Analysismentioning

confidence: 99%

Measurement of short-term changes in the fat content of the body: a comparison of three methods in patients receiving intravenous nutrition

et al. 1984

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1. Three methods of measuring changes in body fat were compared in seventeen patients undergoing a 2-week course of intravenous nutrition. Patients received all nutrition intraveneously at a steady rate of infusion, calculated to supply energy at a rate equal to 1.5 times the resting metabolic expenditure measured before feeding. Fat change was estimated from measurements of skinfold thickness, by isotopic methods (neutron-activation analysis and dilution of tritiated water) and by daily analysis of expired gases.2. The mean (with 1 SEM) gain in fat over the 2-week period was 1.14 (0.30) kg for skinfold measurement, 0.53 (0.62) kg for isotopic determination and 1.29 (0.22) kg for expired-gas analysis. There were no significant differences between the mean gains in fat measured by the three methods.3. The results show that expired-gas analysis is the most sensitive technique, measuring change in fat content with an estimated precision of 0.26 kg. The isotopic method is less sensitive, with a precision of 2.38 kg, but provides a detailed description of body composition. In contrast to these highly-specialized techniques, both of which have limited application, the simple technique of measurement of skinfolds occupies an intermediate position of sensitivity, with a precision for measuring change in fat content of 0.85 kg, and also has the potential to measure total body fat content.

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A Technique for measuring total-body nitrogen in clinical investigations using the 14N(n,2n) 13N reaction

Cited by 42 publications

References 9 publications

Effects of Irradiation Temperature and Irradiation Time on ¹³N-Compounds Produced by Recoil Protons in Benzene and Cyclohexane

Effects of Irradiation Temperature and Irradiation Time on ¹³N-Compounds Produced by Recoil Protons in Benzene and Cyclohexane

Clinical Measurement of Body Composition Using In Vivo Neutron Activation Analysis

Measurement of short-term changes in the fat content of the body: a comparison of three methods in patients receiving intravenous nutrition

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A Technique for measuring total-body nitrogen in clinical investigations using the 14N(n,2n) 13N reaction

Cited by 42 publications

References 9 publications

Effects of Irradiation Temperature and Irradiation Time on 13N-Compounds Produced by Recoil Protons in Benzene and Cyclohexane

Effects of Irradiation Temperature and Irradiation Time on 13N-Compounds Produced by Recoil Protons in Benzene and Cyclohexane

Clinical Measurement of Body Composition Using In Vivo Neutron Activation Analysis

Measurement of short-term changes in the fat content of the body: a comparison of three methods in patients receiving intravenous nutrition

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Effects of Irradiation Temperature and Irradiation Time on ¹³N-Compounds Produced by Recoil Protons in Benzene and Cyclohexane

Effects of Irradiation Temperature and Irradiation Time on ¹³N-Compounds Produced by Recoil Protons in Benzene and Cyclohexane