Search Results

You are looking at 1 - 7 of 7 items for

  • Author or Editor: F. Lux x
  • Refine by Access: All Content x
Clear All Modify Search

Résumé  

On a étudié par analyse par activation le comportement des éléments de l'acier V4A dans des tissus intoxiqués par les métaux. V4A: Fe, Cr, Ni, Mo, Ag et Ta comme métaux purs implantés, et Co, Zn et Sb comme oligoéléments. Pour la recherche du Mn, le24Na a été séparé radiochimiquement. Les limites de détection se situent entre 0,005 ppm (Ta) et 5 ppm (Fe). D'après les résultats des analyses, on peut déduire un processus de corrosion intercellulaire transcristallin du matériau implanté suivi d'une disparition rapide des constituants simples. Seul le Fe est accumulé dans les cellules sous la forme d'un composé biologique qui se dégrade lentement. La teneur en Zn, oligoélément essentiel, est remarquablement diminuée dans le tissu. Cela peut être la conséquence du déplacement du zinc lié aux enzymes par les constituants implantés, provoquant des changements dans les processus enzymatiques qui jouent un rôle déterminant dans le développement de l'intoxication métallique.

Restricted access

Abstract  

A computer program has been worked out for the following requirements: (1) The program is to render a listing of the elements detected, together with their respective concentrations, not just an evaluation of the gamma-spectrum (peak energies and areas). (2) There should be no necessity to intermediate decisions, i.e. execution of the program should be possible by auxiliary personnel. (3) Gamma-ray spectra recorded under widely different conditions should be amenable to evaluation. This implies a large range of variation of the number of channels per peak. (4) In order to have the most extensive capability of executing multi-element analyses instrumentally, it must be possible to evaluate complex spectra with many superpositions. The program involves the fitting of Gaussians. It is shown that this evaluation method gives more precise peak area determinations than the summation method and also yields reasonable results in the case of strong superposition.

Restricted access

Abstract  

Thermal and epithermal neutron activation analysis has been applied to determine the concentrations of magnesium, aluminium, phosphorus, copper and manganese in two biological fluids: blood serum and market milk. Both epithermal neutron irradiation and radiochemical separation (a chromatographic column of HAP) were used to get rid of the interferences from 24-Na. Strongly acidic solutions of the irradiated samples were passed through the columns of HAP, where sodium was completely adsorbed while, Al, Cu, Mg and Mn were eluted with an efficiency of 99±1%. Since both Al and P were determined through the formation of28Al (2.24 min) thermal and epithermal neutron activation have been applied in order to determine the contribution of each radionuclide to28Al activity. The determination of Mg, Al and P in milk samples was done instrumentally, whereas in the case of blood serum with higher concentration of Na, a radiochemical separation is essential in both cases. The concentrations of Al, Cu, Mg, Mn and P in blood serum and market milk were found to be 0.24±0.02 and 1.85±0.09 g Al/ml, 1.35±0.04 and 0.068±0.005 g Cu/ml, 22.9±1 and 98.9±8.6 g Mg/ml, 22±3 and 16±2 ng Mn/ml and 167±13 and 865±32 g P/ml, respectively.

Restricted access

Abstract  

Instrumental neutron activation analyses have been carried out on tissues adjacent and distant from metal implants. From the time-dependence of the concentrations of the corrosion products some conclusions have been drawr on the routes of metal transport from the implant. Additionally, the behaviour of haematoma iron has been shown as well as the dependence of the zinc concentrations on different biochemical processes, during implantation and then at the following stages of the development of the metallosis tissue.

Restricted access

Abstract  

In our determination of trace element contents of animal tissue by neutron activation analysis in the course of structure-activity relationship studies on platinum containing cancer drugs and wound healing we have tried to minimize the blank values that are caused by different sources of contarnination during surgery, sampling and the activation analysis procedure. The following topics have been investigated: the abrasions from scalpels made of stainless steel, titanium or quartz; the type of surgery; the homogenisation of the samples before irradiation by use of a ball mill; the surface contaminations of the quartz ampoules that pass into the digestion solution of the irradiated samples. The appropriate measures to be taken in order to reduce the blank values are described. The results of analyses performed under these conditions indicate the effectiveness of the given measures, especially shown by the low values obtained for the chromium contents of the analysed muscle samples.

Restricted access

Abstract  

As part of an examination of the cytostatic effects of 1,2-diarylethylenediamine-platinum(II)-complexes the contents of platinum and biologically essential trace elements of tumour tissue and different organs were determined. The activation analysis procedure — separation of32P, isolation of199Au and99Mo — is described. In the course of a pharmakokinetical experiment with tumourbearing rats (DMBA induced hormone-dependent tumours) the desired enrichment of the administered drug in the tumour tissue was found. Changes of the trace element level of tumour tissue were found for hormone-dependent MXT-mammary tumours on mice.

Restricted access

Abstract  

Instrumental neutron activation analysis was used for the determination of several trace elements in blood and tissue samples. Results are reported for calcium and iron, for which remarkable changes of the concentrations in the affected tissues were found. The levels and the changes with time of these concentrations can be explained with a participation of the two elements in the following processes: Calcium: 1. Fibrin formation in fracture haematoma blood (FHB) and in the crust of punch-hole wounds in the skin (rats). 2. Haemolysis in FHB-deposits (rabbits). Iron: Formation of collagen in fascia and muscle incision wounds (rabbits). The iron enrichments in the area of complication-free wound are not predominantly caused by a wound haematoma.

Restricted access