[en] Phagocytosis in vivo and in vitro of a suspension of chromic phosphate (III) labeled with "5"1Cr and "3"2P is studied. The radioactive particles dispersed in a media of 2 % gelatin in acetate buffer pH 4-4.5 have a predominant size of 0.8 μm and 5 μm. According with biodistribution experiments in rats after 30 minutes near the 80 % of radioactivity is registered in the liver, probably associated with phagocytosis of the particles by liver Kupffer cells. Is also showed that the suspension particles are phagocytized in vitro by mouse peritoneal macrophages. This facts indicate that the studied suspension have appropriate characteristics to be used in radiosynoviorthesis according to the principal action mechanism described for this procedure, particles phagocytosis by cells present in the inflamed synovium. (author)

[en] Chronic sinovitis, a frequent complication in rheumatoid arthritis and hemophilia, is successfully treated by means of intraarticular injections of radioactive dispersions (radiosynoviorthesis). In Cuba, a formulation of chromic phosphate labeled with "3"2P is used. In order to scale up the process, improve the technology and obtain formulations with other radionuclides, the reaction, based on the reduction of Cr(VI) to Cr(III) with sulphite ions in presence of ions phosphate is studied. If the relationship Na_2SO_3/ CrO_3 is 18.5 times, the precipitation takes place at room temperature roughly at two hours and the pH increases at the beginning and then remains constant at 7.63 because of the buffer action of the sulphite. It was established that the reduction of Cr(VI) to Cr(III) at this pH is a second order reaction. The formation of insoluble species of chromium and phosphor, favors the reduction. At 70 ℃ the precipitation occurs immediately. Using the method of radioactive indicators, it was established that the relationship Cr/P in the precipitate, at room temperature and at 70 ℃ is 1.6. In this case, each component of the relationship and the mass diminish in 8 %, which indicates we are probably in presence of the same product. The heat accelerates the formation of the precipitate and partially dissolves it. If Na_2SO_3/ CrO_3 = 1.5, and the pH value around 5, the precipitate is formed immediately at room temperature. Under the used experimental conditions, the chromium species in the precipitate increase as the pH increases. Possible compositions for the obtained products are suggested. (author)

[en] The oncogenic power of ³²P was demonstrated in salivary glands. An intraglandular injection of 0.25 mCi of chromic colloidal phosphate (³²P) was administered to young adult Wistar rats. Seven months post-injection, tumors began to appear in the neck region in 64% of the rats. The tumors were sarcomas (50%), carcinomas (35.70%), and carcino-sarcomas (14.28%). (author)

No abstract available

[en] With an objective of understanding the differences in the capacity retention behavior and cycle life of cathode consisting transition metal phosphate, Cr_0.5Nb_1.5(PO₄)₃, active material and the binder polyvinylidene fluoride (PVDF) or polytetrafluoroethylene (PTFE), the role of these binders have been analyzed. An electrochemical analysis of the active material mixed with the binders PVDF or PTFE reveals that the PTFE cell experiences an additional discharge capacity of 93 mA h g^-1 during the discharge cycle compared to the PVDF cell. The results of X-ray photoelectron spectroscopy studies of the PTFE mixed cathode reveals nearly the same intensity of F (1s) spectra for before and after discharge cycles suggests that the fluorine atom is not decomposed but permits high utilization of the reactant to be achieved in the cathode during discharge/charge cycles. A remarkable improvement in cell performance in terms of capacity and cycle life for PTFE suggests that the binder PTFE should be an attractive candidate in lithium batteries than that of PVDF

[en] A method of brachytherapy of the CNS with Chromic Phosfate (32P) in colloidal form (CROP) introduced in the subarachnoid space was developed. 90 rabbits were used and colloids were injected through a cysternal tap The permanence and uniform distribution of the colloid in the pio-arachnoid membrane along the whole subarachnoidal space and ventricular ependyma was asserted with autoradiographs and histological sections with stripping film techniques. The distribution of 32P in liver (10%), spleen (7%) and bone marrow (2%) and other organs has no significant effects. The perfect tolerance to the injection of colloids of fine particles with less than 100 nm, (CROP) was proved and no severe neurotoxic effects where observed. When colloids with particles larger than 100 nm were used this undesirable effects were seen. With very high doses, no edema nor lesions could be demonstrated in histological studies of nervous cells or nervous tissue. Up to 6 months the animals did not present neurological symptoms attributable to CROP in that period, even with repeated applications (Au)

[en] A simple and precise method is presented for the radioassay of chromic phosphate ³²P suspension by Cerenkov counting. An aliquot is weighed, dissolved, diluted, and then counted directly in a conventional liquid scintillation counter. The internal standard technique is used to provide color quench correction. This method is particularly useful for high specific activity samples. The standard deviation for the analysis of three aliquots, each determined in triplicate, was 1.9 percent

[en] It was obtained for the first time a suspension of chromium Phosphate (III) labelled with ³²P, with predominant size of particles among 5-10 μm, potentially useful in the treatment of solid tumors and Radiosynoctomy. A dispersion was obtained with prevalence of sizes of the colloidal order with 80% above 0,2 μm, potentially useful for Radiosynovectomy

No abstract available

[en] The possibility of determining the changes in the radius, the surface of a particle and the thickness of a foil in chemical reaction on the basis of transmission Moessbauer spectra is suggested. The ratio of the areas of the partial Moessbauer spectra is equivalent to the change in the quantity of a substance containing Moessbauer atom. Calculations to estimate the particle size changes were made for the reaction between iron powder and either aluminophosphate or chromophosphate or alumino-chromophosphate. This method may be useful in studying corrosion processes, solid phase reactions. (V.N.)