[en] Diagnosis of renal graft acute rejection is made mainly by clinical signs, humoral and functional changes, and is confirmed by histopathological studies. Many efforts have been made to find a radiopharmaceutical for early diagnosis of renal graft rejection. 99mTc-ior t3 monoclonal antibody was evaluated as a radiotracer in renal graft acute rejection. Schwarz's method was used with different molar relations 2ME:IgG and different tin-chelates were explored. The selected formulation was studied by chromatography and challenge studies. Once proved the quality of the radiopharmaceutical a freeze-dried Kit was performed. Its radiochemical purity and stability was studied for several months. FPLC and immunoreactivity studies were included. The sterility and apirogenicity was certified by the Center of Research and Development of Drugs. A clinical trial was started with patients who have received a renal graft eleven days before. An amount of 1.1 GBq of 99mTc-ior t3 MoAb was administered and planar scintigraphic images were recorded. A molar relation of 2000:1 (2ME:IgG) with 30 min produced the best reduction of the MoAb. From the different tin-chelates, the tin-pyrophosphate produced the highest radiochemical purities. The MoAb freeze dried Kit contains 1.0 mg of protein and 14 ug of Sn+2, this quantities guaranteed a shelf life of 6 months. The quality controls and challenge studies showed purity higher than 95.0% and a per cent of dissociation close to 20% was seen with DTPA, 80% with HSA and 48% with Cys. Our preliminary immunoscintigraphic results showed a good correlation among scintigraphy, a high rate of counts Renal Graft/Opposite side and the cause of graft loss. The small number of cases does not permit to make a definite conclusion. However, in some clinical situations the use of 99mTc-ior t3 MoAb could help as an early and specific non-invasive diagnosis of renal graft rejection. (author)

[en] ^99mTc-tetrofosmin was developed for myocardial perfusion imaging. However, it has been suggested that this cationic tracer may be of value as a tumor-imaging agent. Very little is however known about the mechanism of uptake of ^99mTc-tetrofosmin in heart tissue of tumor cells. We studied in-vitro the uptake of this radiopharmaceutical in breast cancer-, sarcoma- and melanoma cell lines. The influence of density of tumor cells, temperature- and time of incubation on the radioactivity uptake were analysed. In these tumor cell lines the uptake of ^99mTc-tetrofosmin was highest at a cellular density of 1.10⁶ cell/ml and at a temperature of incubation of 37 deg. C. This indicates that the uptake of ^99mTc-tetrofosmin by these tumor cells occurs by a metabolism-dependent process, probably related to mitochondria, besides cation channel transport. ^99mTc-tetrofosmin scintigraphy might thus be useful for detecting and imaging at a very early clinical stage these malignant tumors. (author)

[en] Five types of magnetic particles without or with aldehyde, amino and carboxyl functional groups, respectively were used to immobilize first or second antibody by three models, i. e. physical adsorption, chemical coupling and immuno-affinity, forming four types of magnetic particle antibodies. The second antibody immobilized on polyacrolein magnetic particles through aldehyde functional groups and the first antibodies immobilized on carboxylic polystyrene magnetic particles through carboxyl functional groups were recommended to apply to RIAs and/or IRMAs. Streptavidin immobilized on commercial magnetic particles through amino functional groups was successfully applied to separating specific PCR product for quantification of human cytomegalovirus. In the paper typical data on reliability of these magnetic particle ligands were reported and simplicity of the magnetic particle separation technique was discussed. The results showed that the technique was a reliable and simple tool for RIA/IRMA and quantitative PCR assay. (author)

[en] The preparation and labelling procedures of ¹⁵³Sm-hydroxyapatite (¹⁵³Sm-HA) are described in this paper. Hydroxyapatite (HA) was prepared and studied as a radiosynovectomy agent. HA particles were prepared from the reaction of calcium nitrate and ammonia phosphate at high pH Samarium-153 labelling was done in two steps with citric acid. A serie of experimental conditions, such as specific activity, citric acid mass, radioactive solution volume, in-vitro stability, have been carried out. Radiolabelling efficiency was greater than 95%. In vitro studies showed high stability (≥99%). Animal studies showed a good retention in the synovium, with a very low extra-articular leakage over 6 days after administration. (author)

[en] Spleen targeted In-114m, using labelled autologous lymphocytes, has produced a significant antitumour effect in patients with chronic lymphocytic leukaemia and Non-Hodgkins lymphoma (Sharma et al, Anti-Cancer Research 17, 1815-1822,1997). Heat treated red blood cells could be used as alternative vectors for splenic targeting of In-114m, making the technique easier, more universally applicable and furthermore, may reduce the myelosuppression seen with labelled lymphocytes. Red blood cells from HO3T rats were labelled with In-114m-oxine, incubated at 49.5 deg. C for 15 minutes and their distribution investigated in the spleen, liver and blood or recipient animals. The splenic uptake in the spleen at 24h was 64.08%, remained unchanged at 7 days, cleared slowly after that, clearly demonstrating the specificity of HTRBC to target In-114m to the spleen. The depletion of peripheral blood lymphocytes was measured in two groups of HO3T rats following the administration of 1.6 and 3.2 MBq of In-114m-HTRBC respectively. Compared to the controls, ∼ 70% of lymphocytes were depleted in the treated animals within one week and remained unchanged for 6 weeks. Using a rat T-cell lymphocytic leukaemia model, with resemblance to the clinical disease, an anti-leukaemic effect of his method of treatment, was monitored. An average life span of the treated group (1.85 MBq of In-114m-HTRBC) was 17.1 days, compared to the 13.5 days for the untreated group. These results are similar to the ones reported by targeting In-114m with labelled lymphocytes. In summary, the project has shown that In-114m-HTRBC can be used to deposit the radioactivity, selectively in the spleen, which in turn, depletes the peripheral blood lymphocytes and produces an anti-leukaemic effect in terms of enhanced life span. The bone marrow toxicity from In-114m therapy is under investigation and a pharmacokinetic study in selected cancer patients is planned following which, a clinical trial will be considered. (author)

[en] Using the effective field theory with a probability distribution technique that accounts for the self-spin correlation functions, the layer longitudinal magnetizations and quadrupolar moments of a spin-1 Ising film and their averages are examined. These quantities as functions of the temperature, the ratio of the surface exchange interactions to the bulk ones, the strength of the transverse field and the film thickness are calculated numerically and some interesting results are obtained. (author)

[en] The solution of BBGKY hierarchy of kinetic equations is defined through particle method solution of Vlasov equation. (author)

[en] The emission rate of fermions from 2+1 dimensional BTZ black holes is shown to have a form which can be reproduced from a conformal field theory at finite temperature. The rate obtained for conformally coupled fermions is identical to the rate of non-minimally coupled fermions emitted from a five dimensional black hole, whose near horizon geometry is BTZ x M, where M is a compact manifold. (author)

[en] The current electricity crisis in Ghana has mandated a holistic approach towards meeting the energy demand of the country. In this paper, a brief review of the various technologies for electricity generation is presented and the role of the chemist in each technology is identified. An emphasis is placed on the nuclear option as a plausible component of a comprehensive energy portfolio and the role of the chemist in each step of the nuclear fuel cycle is outlined. The challenges facing the chemists in the country are enumerated and recommendations for ensuring the incorporation of the nuclear option into the total energy mix of the country are presented. (author)

[en] The results of the aviation measurement of the gamma-radiation are presented in the form of the maps of iso-lines of the concentration of the natural radioactive elements (potassium, uranium, thorium) and artificial radionuclides (cesium-137, cesium-134). From the obtained dates the maps of dose rate of the gamma-radiation in the air are calculated, of the dose equivalent rate and the map of the fraction of the dose equivalent rate from the natural elements potassium, uranium, thorium. The natural radioactivity of the minerals in the Great Bratislava region, especially for the extreme low values of the contain of the thorium, does not amount the average values of the radioactivity of the Earth crust. The area activity of cesium-137 are in the range 2 - 10 kBq.m^-2 and cesium-134 is 1 - 2.5 kBq.m^-2. From the point of view of the summary level of the external irradiation from the Earth surface the measured zone as relative even is evaluated, in the range 10-100 nSv.h^-1. The total average level of the dose rate of the external irradiation of man (inclusively from the cosmic radiation 40-50 nSv.h^-1) in the conditions of Bratislava is 100 nSv.h^-1. The contribution of external component of the irradiation is 40-100 nSv.h^-1 (0.1-0.3 mSv.y^-1). The dose equivalent commitment of internal component from the cesium-137 is for the all age category of the population under the level negligible risk 0.01 mSv.y^-1