Electron injection into titanium dioxide by panchromatic dirhodium photosensitizers with low energy red light.

Two new Rh2(ii,ii) dyes were synthesized and anchored to TiO2 for charge injection upon irradiation. The 1ML-LCT (metal/ligand-to-ligand charge transfer) excited state is populated upon excitation, which decays to the corresponding 3ML-LCT state. Ultrafast electron injection into TiO2 from the Rh2(ii,ii) dyes was achieved with low energy, red light excitation.

Recoil effect on beta-decaying in vivo generators, interpreted for (103)Pd/(103m)Rh.

The use of Auger emitters as potential radiopharmaceuticals is being increasingly investigated. One of the radionuclides of interest is (103m)Rh, which can be produced from (103)Ru or (103)Pd in an in vivo generator. A potential problem, however, is the recoil of the (103m)Rh out of the carrier molecule and even out of the target cell. In order to determine the likelihood of this happening in the (103)Pd/(103m)Rh, case calculations were made to prove that this does not happen. The equations were generalised for all radionuclides with an atomic mass of 10-240 as a tool for determining the recoil threshold of any beta-emitting radionuclide.

Encapsulation and release of rhodium(II) citrate and its association complex with hydroxypropyl-beta-cyclodextrin from biodegradable polymer microspheres.

Rhodium(II) carboxylates and their derivatives constitute a promising class of second-generation transition metal compounds with anticancer properties. While most transition metal anticancer compounds chelate DNA and cause extensive chromosomal damage, rhodium(II) carboxylates act on the enzyme DNA polymerase alpha and hence cause minimal chromosomal damage. Rhodium(II) citrate, a recent member of the rhodium(II) carboxylate family is highly promising as an antitumor agent. However, due to its high water solubility, a high systemic dose is necessary to achieve efficacy. In this paper, we have explored the complexation of rhodium(II) citrate with hydroxypropyl-beta-cyclodextrin as a means to improve encapsulation and release kinetics from poly(dl-lactic-co-glycolic) acid (PLGA) and poly(anhydride) microspheres. We observed that complexation of rhodium(II) citrate with hydroxypropyl-beta-cyclodextrin significantly increased both the encapsulation efficiency and duration of release in both polymer systems.

Comparative nephrotoxic effects of cis-platinum (II), cis-palladium (II), and cis-rhodium (III) metal coordination compounds in rat kidneys.

A Sprague-Dawley rat kidney perfusion technique was used in situ to study the effects of cis-dichloro-diamine platinum, PdCl2 (2,6-diaminopyridine), and RhCl3 (2,6-diaminopyridine) on sodium and calcium retention in the whole kidney. The technique involves perfusion of both kidneys via the abdominal aorta and then through the right and left renal arteries and dorsal aorta. Compared to controls, kidneys perfused independently with the three coordination compounds showed approximately equal to 45% decrease and approximately equal to 117% increase in Na+ and Ca2+ retention, respectively. Perfusates containing the coordination compounds in addition to 15 mM ouabain showed approximately equal to 76% decrease in Na+ and insignificant increase in renal Ca2+ retention. Hence, one can rule out the presence of voltage-gated Ca(2+)-channels at the basolateral side due to membrane depolarization. These results suggest that the three metal coordination compounds showed identical nephrotoxic effects on the handling of Na+ and Ca2+ ions by inhibiting both the Na(+)-Ca(2+)-anti-porter and the Na(+)-H(+)-exchanger with laxing effects on nonvoltage-gated Ca(2+)-channels at the basolateral side. However, their effects on the Na(+)-K(+)-ATPase and the Na(+)-Ca2+ symporter was insignificant.

Citrato do ródio: II. Modelo de agente inflamatório / Rodium citrato: II. Inflamatory agent model

o citrato de ródio II sintetizado na procura de complexos de ródio com atividade anti-tumoral e baixa toxicidade. Näo foram observados mortes ou outros sinais de toxicidade após injeçäo de 260 mg/Kg de citrato de ródio II, intra-peritonial em camundongos observados durante 14 dias. A substância provaca um quadro inflamatório que se caracteriza por edema persistente por 24 horas, quando injetada na pata de ratos. Injetada na cavidade peritonial há aumento de neutrófilos segmentados no exudato peritoneal bem como aumento significativo no número de macrófagos espraiados

[Radiotherapy of intraocular tumours, particularly of melanoma of the choroid (author's transl)]. / Radiotherapie der intraokularen Tumoren, insbesondere bei Aderhautmelanom.

From 1964 to 1976 a number of 131 patients, suffering from melanoma of the choroid have been treated with 106Ru/106Rh beta-ray applicators. In 81 cases (61.8%) this treatment has been successful. 26 eyes (19.9%) had to be enucleated in spite of the irradiation. 24 patients (18.3%) died, 13 of them of metastases. Only in 46 patients, out of 81, we have reached total destruction of the tumor with flat chorioatrophic scar. In 27 cases visual acuity of 1.5 to 0.5 could be preserved. Radiogenic late complications in the capillary system with disturbances of the retinal blood circulation were the cause of visual deterioration. The 107 surviving patients were controlled during a period of 6.5 years in the average. Survival rate 91.2% after 5 and 84% after 10 years. Another group of 214 patients with melanoma of the choroid, who had been treated from 1955 to 1970 by enucleation reached a survival rate of 72% after 5 years. Treatment with 106Rh beta-irradiation therefore leads to no increased danger of metastases. The following indications for this treatment are suggested: 1. Prominence of the tumor not exceeding 5 mm, largest diameter at its base not more than 15 mm. 2. Distance of the dorsal edge of the tumor at least 1-2 optic disc diameters from the nerve head. 3. Peripheral delimitation against the ciliary body. 4. No tumor growth outside the eye.

[Complications of the irradiation therapy with beta applicators in malign melanomas (author's transl)]. / Komplikationen bei der Strahlentherapie des intraokularen Melanoms mit Beta-Applikatoren (106Ru/106Rh).

Depending on prominence and localization of malign melanomas of the choroid, there are - besides enucleation - other clinical treatments possible. Irradiation therapy with beta applicators (106Ru/106Rh) gives also radiogenous complications. But contrarily to a treatment with cobalt-60 applicators, these complications are less important.

The metabolism of rhodium(II) acetate in tumor-bearing mice.

Rhodium(II) acetate has been shown to have carcinostatic activity in Swiss mice bearing Ehrlich ascites tumors. For metabolic studies, single therapeutic doses of rhodium(II) [1-14C]acetate that had been given i.p. implantations 3 days previously of 50-fold 10(6) Ehrlich ascites tumor cells. The tissue distribution and excretion of the rhodium (measured by atomic absorption spectrometry) and the acetate (measured by 14C label) were followed at designated time intervals up to 24 hr after injection. Rhodium(II) acetate, a neutral cage complex, breaks down to rhodium and acetate ionic species within 2 hr after i.p. injection, as measured by the rapid exhalation of 14CO2. Both the rhodium and 14C label disappear rapidly from the ascites fluid, with a small but variable amount of each species being incorporated into the tumor cells. Both species were detected mainly in the blood plasma, and the primary organ of deposition was the liver. No measurable quantity of rhodium was found in the brain tissue. During the first 24 hr following drug administration, only 5% rhodium was eliminated in the urine.