Uranium colloid analysis by single particle inductively coupled plasma-mass spectrometry.

Uranium single particle analysis has been performed by inductively coupled plasma-mass spectrometry (ICP-MS) and the performances are compared with that provided by scanning electron microscopy and single particle counting. The transient signal induced by the flash of ions due to the ionisation of an uranium colloidal particle in the plasma torch can be detected and measured for selected uranium ion masses ((238)U(+), (235)U(+) or (254)[(238)U(16)O](+)) by the mass spectrometer. The signals recorded via time scanning are analysed as a function of particle size or fraction of the studied element or isotope in the colloid phase.

Thorium colloid analysis by single particle inductively coupled plasma-mass spectrometry.

Thorium colloid analysis in water has been carried out by a single particle mode using inductively coupled plasma mass spectrometry (ICP-MS). The flash of ions due to the ionisation of a thorium colloidal particle in the plasma torch can be detected and measured in a time scan for (232)Th (+ ) or (248)[ThO] (+ ) according to the sensitivity required by the mass spectrometer. The peaks of the recorded intensity of the MS signal can be analysed as a function of the particle size or fraction of the studied element in the colloid phase.

Decarboxylation and carboxylation of pyruvate in the living mice.

Mice received intravenously [1- or 2-14C]acetate, [1-, 2- or 3-14C] or [2-14C]pyruvate and were killed 1, 3, 5 or 15 min later. The radioactivity of CO2 or HCO3- of liver or carcass as well as the radioactivity of blood glucose were measured. The ratio of the radioactivity found in these compounds after [3-14C] or [2-14C-A1pyruvate injection suggests that in the fed aminals: 1.

Production of CO2 in the living mouse immediately after injection of 1- or 2-14C acetate.

Three groups of mice, normally fed, fasted and fed after a fasting period are injected intravenously with either 1- or 2-14C acetate. The respiratory 14CO2 as well as that of the liver, the adipose tissue and the carcass are collected after 3 min and the radioactivity measured. A determination is also made of the radioactivity of the tissue fatty acids and, for two groups of mice, of the circulating glucose.

[Rapid production of a biotin deficiency in mice].

This work describes a rapid method for the production of a biotin-deficiency in mice. Besides classical morphological symptoms, a decrease of activities of some biotin-dependent enzymes was also observed. The biotin-enzymes are not inhibited at the same extent in a same organ and the metabolic changes do not always follow the enzymatic modifications.

[Not Available].

Mice were given glucose-U-(14)C and the radioactivity of triglyceride and phospholipid glycerol and fatty acids was measured 30 sec, 3 or 30 min after the i.v. administration in liver microsomes and supernatant.

[Not Available].

The synthesis of fatty acids in mitochondria, microsomes and supernatant of mice liver was studied after administration of glucose 14C or (3)H, acetate 14C or 3H and pyruvate 14C.The results suggest that the cellular structures corresponding to the microsomes are the major site of fatty acid synthesis in the liver in vivo.