Rhenium Research Papers - Academia.edu (original) (raw)

Introduction: Rhenium-188-HEDP (188 Re-HEDP) is a therapeutic radiopharmaceutical for treatment of osteoblastic bone metastases. No standard procedure for the preparation of this radiopharmaceutical is available. Preparation conditions... more

Introduction: Rhenium-188-HEDP (188 Re-HEDP) is a therapeutic radiopharmaceutical for treatment of osteoblastic bone metastases. No standard procedure for the preparation of this radiopharmaceutical is available. Preparation conditions may influence the quality and in vivo behaviour of this product. In this study we investigate the effect of critical process parameters on product quality and stability of 188 Re-HEDP. Methods: A stepwise approach was used, based on the quality by design (QbD) concept of the ICH Q8 (Pharmaceutical Development) guideline. Potential critical process conditions were identified. Variables tested were the elution volume, the freshness of the eluate, the reaction temperature and time, and the stability of the product upon dilution and storage. The impact of each variable on radiochemical purity was investigated. The acceptable ranges were established by boundary testing. Results: With 2 ml eluate, adequate radiochemical purity and stability were found. Nine ml eluate yielded a product that was less stable. Using eluate stored for 24 h resulted in acceptable radiochemical purity. Complexation for 30 min at room temperature, at 60 °C and at 100 °C generated appropriate and stable products. A complexation time of 10 min at 90 °C was too short, whereas heating 60 min resulted in products that passed quality control and were stable. Diluting the end product and storage at 32.5 °C resulted in notable decomposition. Conclusion: Two boundary tests, an elution volume of 9 ml and a heating time of 10 min, yielded products of inadequate quality or stability. The product was found to be instable after dilution or when stored above room temperature. Our findings show that our previously developed preparation method falls well within the proven acceptable ranges. Applying QbD principles is feasible and worthwhile for the small-scale preparation of radiopharmaceuticals.

In the last years ruthenium tetroxide is increasingly being used in organic synthesis. Thanks to the fine tuning of the reaction conditions, including pH control of the medium and the use of a wider range of co-oxidants, this species has... more

In the last years ruthenium tetroxide is increasingly being used in organic synthesis. Thanks to the fine tuning of the reaction conditions, including pH control of the medium and the use of a wider range of co-oxidants, this species has proven to be a reagent able to catalyse useful synthetic transformations which are either a valuable alternative to established methods or even, in some cases, the method of choice. Protocols for oxidation of hydrocarbons, oxidative cleavage of C-C double bonds, even stopping the process at the aldehyde stage, oxidative cleavage of terminal and internal alkynes, oxidation of alcohols to carboxylic acids, dihydroxylation of alkenes, oxidative degradation of phenyl and other heteroaromatic nuclei, oxidative cyclization of dienes, have now reached a good level of improvement and are more and more included into complex synthetic sequences. The perruthenate ion is a ruthenium (VII) oxo-species. Since its introduction in the mid-eighties, tetrapropylammon...

Ten sulphide inclusions in three diamonds from the Zimmi (West Africa) alluvial diamond locality were analysed for their bulk Fe-Cu-Ni-Co contents and Re-Os isotopic compositions. The host diamonds are exceptionally rare, Ib types that... more

Ten sulphide inclusions in three diamonds from the Zimmi (West Africa) alluvial diamond locality were analysed for their bulk Fe-Cu-Ni-Co contents and Re-Os isotopic compositions. The host diamonds are exceptionally rare, Ib types that still preserve isolated nitrogen (C centres), rather than more common nitrogen pairs (A centres) and nitrogen aggregates (B centres). C centres in Zimmi diamonds require that they did not experience temperatures above 850 C for any extended period. Such diamonds make up less than 0.1 % of natural gem diamonds and have never before been dated. The sulphides are pyrrhotite-rich, have low Ni and Os contents, and radiogenic 187Os/188Os, all features characteristic of eclogitic sulphides. Each diamond has 3 to 4 individual inclusions. 187Re/188Os and 187Os/188Os data fall along three individual ~650 Ma age arrays that represent essentially 3-point or 4-point mineral isochrons for each diamond - unambiguously dating the time of diamond formation. The ~650 Ma age correlates with the timing of Neoproterozoic assembly of Gondwana, recorded in the Rokelide orogen along the SW margin of the West African craton. The initial 187Os/188Os of the three age arrays fall between 1.6 and 2.2 and are highly radiogenic compared to chondritic mantle at 650 Ma. Along with low Re/Os ratios, this data suggests that sulphides were not derived from Neoproterozoic subducting slabs, but rather from older eclogitic material already present in the West African lithospheric mantle. The age of the diamonds and their nitrogen substitutional characteristics, along with their residence in a lithospheric mantle with a normal cratonic geotherm (determined here from Koidu clinopyroxene xenocrysts) suggests that after diamond formation they were rapidly exhumed to shallower depths in the lithosphere. This likely occurred through tectonic uplift following Neoproterozoic continental collision.

Affibody molecules are small (7 kDa) nonimmunoglobulin scaffold proteins with favorable tumor-targeting properties. Studies concerning the influence of chelators on biodistribution of (99m)Tc-labeled Affibody molecules demonstrated that... more

Affibody molecules are small (7 kDa) nonimmunoglobulin scaffold proteins with favorable tumor-targeting properties. Studies concerning the influence of chelators on biodistribution of (99m)Tc-labeled Affibody molecules demonstrated that the variant with a C-terminal glycyl-glycyl-glycyl-cysteine peptide-based chelator (designated ZHER2:V2) has the best biodistribution profile in vivo and the lowest renal retention of radioactivity. The aim of this study was to evaluate (188)Re-ZHER2:V2 as a potential candidate for radionuclide therapy of human epidermal growth factor receptor type 2 (HER2)-expressing tumors. ZHER2:V2 was labeled with (188)Re using a gluconate-containing kit. Targeting of HER2-overexpressing SKOV-3 ovarian carcinoma xenografts in nude mice was studied for a dosimetry assessment. Binding of (188)Re-ZHER2:V2 to living SKOV-3 cells was demonstrated to be specific, with an affinity of 6.4 ± 0.4 pM. The biodistribution study showed a rapid blood clearance (1.4 ± 0.1 perce...

PURPOSE: Lipid nanocapsules (LNC) entrapping lipophilic complexes of (188)Re ((188)Re(S(3)CPh)(2)(S(2)CPh) [(188)Re-SSS]) were investigated as a novel radiopharmaceutical carrier for internal radiation therapy of malignant gliomas. The... more

PURPOSE: Lipid nanocapsules (LNC) entrapping lipophilic complexes of (188)Re ((188)Re(S(3)CPh)(2)(S(2)CPh) [(188)Re-SSS]) were investigated as a novel radiopharmaceutical carrier for internal radiation therapy of malignant gliomas. The present study was designed to evaluate the efficacy of intra-cerebral administration of (188)Re-SSS LNC by means of convection-enhanced delivery (CED) on a 9L rat brain tumour model. METHODS: Female Fischer rats with 9L glioma were treated with a single injection of (188)Re-SSS LNC by CED 6days after cell implantation. Rats were put into random groups according to the dose infused: 12, 10, 8 and 3Gy in comparison with blank LNC, perrhenate solution (4Gy) and non-treated animals. The radionuclide brain retention level was evaluated by measuring (188)Re elimination in faeces and urine over 72h after the CED injection. The therapeutic effect of (188)Re-SSS LNC was assessed based on animal survival. RESULTS: CED of (188)Re perrhenate solution resulted in ...

Radionuclide therapy has proven to be an efficacious palliative treatment for metastatic prostate cancer. Its potential therapeutic possibilities may be substantially increased by combining it with effective radiosensitizing drugs. This... more

Radionuclide therapy has proven to be an efficacious palliative treatment for metastatic prostate cancer. Its potential therapeutic possibilities may be substantially increased by combining it with effective radiosensitizing drugs. This study explores the radiosensitizing properties of cisplatin when combined with 186Re-labeled hydroxyethylidene diphosphonate (HEDP) in the treatment of R3327-MATLyLu prostate cancer cells in vitro. A concomitant incubation during 4 d, combining various concentrations of cisplatin (0, 0.42, 0.83 and 1.67 micromol/L) and 186Re-HEDP (0, 1.84 and 3.69 MBq/mL [0, 50 and 100 microCi/mL, respectively]) was followed by the determination of the cell numbers surviving and the replating of these cells in semisolid agar. The surviving fraction of clonogenic tumor cells after combination treatment clearly showed synergism when analyzed by a panel of three different published analytical methods. In addition, analysis of variance demonstrated a significant interact...

Following the blowout of the Macondo well, a pulse in sedimentation resulted in changes in sedimentary redox conditions. This is demonstrated by downcore and temporal changes in the concentration of redox sensitive metals: Mn, Re, and Cd.... more

Following the blowout of the Macondo well, a pulse in sedimentation resulted in changes in sedimentary redox conditions. This is demonstrated by downcore and temporal changes in the concentration of redox sensitive metals: Mn, Re, and Cd. Sediment cores collected in the NE Gulf of Mexico (GoM) reveal increased sedimentation after the Deepwater Horizon (DWH) blowout. The formation of mucous-rich marine snow in surface waters and subsequent rapid deposition to underlying sediments is the likely cause. Respiration of this material resulted in decreased pore-water oxygen concentration and a shoaled redoxcline, resulting in two distinct Mn peaks in sediments following the event, one typically in the top 10 mm, with the other at 20–30 mm. Most cores near the wellhead reveal this non-steady state behavior for up to two years after the event. Associated with the Mn minimum between the two Mn peaks, a modest (15–30%) enrichment of Re consistent with reducing sediments typically exists. A three-year time series of three stations following the event reveal that sediment Re increased 3–4 times compared to the pre-impact baseline value for two years, indicating sediments are increasingly more reducing for two years. In the third year, Re concentration decreased, suggesting a return towards pre-impact conditions. In select sites where the density of benthic foraminifera was determined, an assemblage-wide decrease occurred coincident with reducing conditions as determined by redox sensitive metals, demonstrating the important consequences of changing redox conditions on benthic ecosystems. Determination of redox sensitive metals will continue to constrain the temporal evolution of reducing conditions, which will serve to document the long-term effects of the spill, and the possible return to pre-event conditions.

Radionuclide bone metastases therapy is a major achievement of nuclear medicine. Development of less radiotoxic and more effective radiopharmaceuticals is therefore a challenge for radiopharmacists and industry. This paper reviews the... more

Radionuclide bone metastases therapy is a major achievement of nuclear medicine. Development of less radiotoxic and more effective radiopharmaceuticals is therefore a challenge for radiopharmacists and industry. This paper reviews the application of rhenium-188 HEDP as a reactor- or generator-produced nuclide for bone metastases therapy.

Mineralogical, electron microprobe analysis and laser ablation-inductively coupled plasma-mass spectrometry data from molybdenite within two porphyry copper deposits (Kalinovskoe and Birgilda) of the Birgilda-Tomino ore cluster (South... more

Mineralogical, electron microprobe analysis and laser ablation-inductively coupled plasma-mass spectrometry data from molybdenite within two porphyry copper deposits (Kalinovskoe and Birgilda) of the Birgilda-Tomino ore cluster (South Urals) are presented. † The results provide evidence that molybdenites from these two sites have similar trace-element chemistry. Most trace elements (Si, Fe, Co, Cu, Zn, Ag, Sb, Te, Pb, Bi, Au, As and Se) form mineral inclusions within molybdenite. The Re contents in molybdenite vary from 8.7 ppm to 1.13 wt.%. The Re distribution within single molybdenite flakes is always extremely heterogeneous. It is argued that a temperature decrease favours the formation of Re-rich molybdenite. The high Re content of molybdenite observed points to a mantle-derived source.