Assessment of metals and metalloids in skin derivatives of volunteers from capital city of Prague, Czech Republic.

Instrumental neutron activation was employed to determine 12 elements (Al, As, Co, Cr, Cu, Fe, Hg, Mn, Mo, Sb, V, Zn) in derivatives of the epidermis (human scalp hair, public hairs and toenails) from 188 women and 74 men of the population of the Capital City of Prague. Statistically significant differences are discussed, occurring during the comparison of groups arranged in terms of various factors (type of material analyzed, age, sex, environmental exposure of the dwelling and/or occupation locality, type of occupation--mental or manual, smoking, alcohol consumption, allergy, hysterectomy and selected diseases). Statistically significantly increased levels of elements in materials coming from Prague areas with higher environmental burden are considered as the most valuable result.

Effects of hemodialysis on bone mineral as followed by using neutron activation analysis.

The purpose of the study was to bring a contribution to the knowledge of physiology and pathophysiology of the bone mineral heteroionic exchange with respect to sodium ions and metabolic diseases, particularly bone diseases. The instrumental neutron activation analysis was employed to follow the ratio of contents Na/Ca in bone samples from dialyzed patients. A formerly elaborated method for the determination of the Na/Ca ratio in undecalcified bone tissue sections obtained from material embedded in polymethylmethacrylate was used. In the reference group the Na/Ca ratio was of 0.021 +/- 0.003, that in patients with the renal osteopathy was of 0.030 +/- 0.007. Results obtained in patients with different types of the renal osteopathy depending on the intensity of the impairment were discussed.

Determination of sodium-to-calcium ratio in mouse femora by INAA.

Within the scope of the study of the heteroionic exchange in the bone mineral, the sodium-to-calcium ratio was established in femora of 55 male ICR mice. The purpose of the work was to establish the precision of the method as well as biological variations, since the authors intend to investigate the sodium-to-calcium ratio on pathophysiological models in the future with a special regard to osteoporosis. The resulting mean value was of 0.02515 +/- 0.00053. The small standard deviation indicates that the ratio is not subject to considerable individual variations. The accuracy of the method was checked by analyzing the reference bone sample IAEA H-5. The results obtained exerted a good agreement with the certified sodium and calcium concentrations.

An application of neutron activation and radiotracer techniques for studying the status of sodium in the bone mineral.

Neutron activation analysis of intact and water-extracted (on boiling) bone (femur) samples made it possible to determine manganese, sodium, potassium and chlorine. A major portion of sodium in contrast to potassium) was retained in the bone, which was in agreement with a well known presence of slowly exchangeable sodium in the bone. Further experiments were carried out with fragments of the femur of rabbits that were administered with the radionuclide 22Na and sacrificed after a sufficient equilibration period. Under conditions of stirring with water at a laboratory temperature, a two-exponential course of the sodium ion release was observed with half time values of 4.36 and 167 hours. An explanation is suggested that in the bone there are actually two fractions of slowly exchangeable sodium, present on the bone mineral crystal surface and bone mineral crystal interior, respectively. The experiments on the bone in vitro can help to bridge a gap between in vitro experiments on synthetic hydroxy apatite and dynamic studies based on the in vivo neutron activation analysis. Results of a complementary experiment with ashed bone samples demonstrated an almost complete abolishment of the sodium ion release, which is in perfect agreement with a known concept of the thermal recrystallization of the bone mineral.

Distribution of radioyttrium in tumor bearing nude mice.

The radionuclide 90Y was produced by the activation of yttrium nitrate in the nuclear reactor core, by the reaction 89Y (n, gamma) 90Y. The radionuclide obtained was characterized with the help of the absorption curve, decay curve and beta - and gamma - ray spectra. A slight admixture cf 89Sr was observed. The organ distribution of the radionuclide produced in tumor-bearing nude mice was established on the basis of measuring ashed tissues, since fresh as well as dried tissues exerted remarkable self-absorption effects. No selective accumulation of the radioyttrium in the tumors was observed for subcutaneously located osteosarcoma and rectal carcinoma. The highest concentrations were found in the lungs, spleen and liver. Thus, our study based on the use of the radioactive tracer 90Y does not support a recommendation to use yttrium ions as a tumor localizer, which was formerly proposed on the basis of the PIXE technique.

Electrophoresis of cells at the interface liquid/liquid.

A new method for measuring the mobility of cells in an electric field is described. The movement of cell samples is carried out at the interface: isotonic phosphate buffer (pH 7.37, mu = 2.214) with Ficoll--the same phosphate buffer without Ficoll. After the voltage is switched on, cells are moving in parallel along the interface. The movement is accomplished by sliding on the denser of these two layers in a flat cuvete. Several samples of cells may be applied and their relative displacement compared. The method was established for human erythrocytes and tannined human erythrocytes.