Brilliant Sm, Eu, Tb, and Dy chiral lanthanide complexes with strong circularly polarized luminescence.
(33/98)
The synthesis, characterization, and luminescent behavior of trivalent Sm, Eu, Dy, and Tb complexes of two enantiomeric, octadentate, chiral, 2-hydroxyisophthalamide ligands are reported. These complexes are highly luminescent in solution. Functionalization of the achiral parent ligand with a chiral 1-phenylethylamine substituent on the open face of the complex in close proximity to the metal center yields complexes with strong circularly polarized luminescence (CPL) activity. This appears to be the first example of a system utilizing the same ligand architecture to sensitize four different lanthanide cations and display CPL activity. The luminescence dissymmetry factor, g(lum), recorded for the Eu(III) complex is one of the highest values reported, and this is the first time the CPL effect has been demonstrated for a Sm(III) complex with a chiral ligand. The combination of high luminescence intensity with CPL activity should enable new bioanalytical applications of macromolecules in chiral environments. (+info)
Dual-label time-resolved fluoroimmunoassay for simultaneous detection of myoglobin and carbonic anhydrase III in serum.
(34/98)
We developed a dual-labeled time-resolved fluoroimmunoassay for simultaneous quantification of myoglobin (Mb) and carbonic anhydrase III (CA III) in serum involving polyclonal antibodies and the fluorescent lanthanides europium (Eu3+) and samarium (Sm3+). This solid-phase immunoassay is based on competition between Eu(3+)- or Sm(3+)-labeled antigen and the sample antigen for polyclonal rabbit antibodies. Standards and patients' samples containing antigen inhibit binding of the lanthanide-labeled antigen to the antibody. A second antibody directed against rabbit IgG is coated on a solid phase and binds the IgG-antigen-lanthanide complex, giving rapid and complete separation of antibody-bound and free antigen. The assay requires only one incubation step. An enhancement solution dissociates Eu3+ and Sm3+ ions from the labeled CA III and Mb, respectively, into a solution where they form highly fluorescent chelates. Spectra of the fluorescent chelates in the microtitration-strip wells were run on a time-resolved fluorometer equipped with filters for Eu3+ (613 nm) and Sm3+ (643 nm), the fluorescence from each sample being inversely proportional to the concentration of antigens. The measurement range for both analytes is from 5 to 1500 micrograms/L. The mean within- and between-assay precisions (CV) were 4.6% and 6.2% for CA III and 5.9% and 7.3% for Mb, respectively. Good correlations were obtained with the results of CA III RIA and a commercial myoglobin RIA kit. (+info)
The management of painful bone metastases with an emphasis on radionuclide therapy.
(35/98)
OBJECTIVE: This review provides an update on the management of painful bone metastases, with an emphasis on radionuclide therapy, and introduces oligometastases and quantitative imaging evaluations for clinical trials. METHODS: The current use of radionuclides, alone and in combination with chemotherapy and radiation therapy for painful bone metastases, is discussed, including toxicity, cost and overall outcomes. RESULTS: Radionuclide therapy is shown to be a useful and cost-effective means of alleviating bone pain in metastatic disease and may be more effective when combined with chemotherapy, bisphosphonates and radiation therapy. Early use of radionuclides in pain therapy may limit cancer progression by inhibiting oligometastases development. Thus, radionuclides can significantly decrease patient morbidity, prolong patient survival, and may decrease the occurrence of new bone metastases. CONCLUSION: Palliative pain therapy is critical for effectively managing bone metastases, with treatment options including analgesics, external beam radiotherapy, chemotherapy and radionuclides. Radionuclide therapy is underutilized. Recent studies using radionuclides with chemotherapy and bisphosponates, or using newer radionuclides or combinations of radionuclides and treatment paradigms (e.g., higher activities, repetitive or cyclic administration, chemo sensitization, chemo supplementation), are encouraging. A comprehensive, inter-disciplinary clinical approach is needed. Clinical collaborations will optimize radionuclide therapy for pain palliation and increase awareness of its benefits. (+info)
Combined use of zoledronic acid and 153Sm-EDTMP in hormone-refractory prostate cancer patients with bone metastases.
(36/98)
PURPOSE: (153)Sm-ethylenediaminetetramethylenephosphonic acid (EDTMP; Quadramet) is indicated for the treatment of painful bone metastases, whereas zoledronic acid (Zometa) is indicated for the prevention of skeletal complications. Because of the different therapeutic effects, combining the treatments may be beneficial. Both, however, accumulate in areas with increased osteoblastic activity. Possible drug interactions were investigated. METHODS: Patients with hormone-refractory prostate cancer were treated with 18.5 MBq/kg (153)Sm-EDTMP in weeks 1 and 3 and with 37 MBq/kg in week 15. Treatment with 4 mg zoledronic acid began in week 3 and continued every 4 weeks through week 23. In weeks 3 and 15, zoledronic acid was administered 2 days before (153)Sm-EDTMP treatment. Urine was collected 48 h after injection of (153)Sm-EDTMP, and whole-body images were obtained 6, 24 and 48 h post-injection. The effect of zoledronic acid on total bone uptake of (153)Sm-EDTMP was measured indirectly by the cumulative activity excreted in the urine in weeks 1, 3 and 15. Biodistribution, safety, tolerability and effect on prostate-specific antigen level were also studied. RESULTS: The urinary excretion in week 3 divided by the urinary excretion in week 1 (baseline) times 100% was mean 98.4 +/- 11.6% (median 96.2%). From week 1 to 15, after four zoledronic acid treatments, the mean ratio was 101.9 +/- 10.7% (median 101.8%). Bioequivalence could be concluded by using a two-sample t test for both per-protocol (n = 13) and full-analysis sets (n = 18). Toxicity was comparable to of monotherapy with (153)Sm-EDTMP. CONCLUSION: Zoledronic acid treatment does not influence (153)Sm-EDTMP skeletal uptake. Combined treatment is feasible and safe. (+info)
Development of sealed cup yoke type dental magnetic attachment.
(37/98)
The purpose of this study was to develop a small cup type yoke magnetic attachment sealed from oral fluid. The magnetic device forms a closed circuit between the magnet, yokes, and keeper. A 3.2 mm phi x 1.4 mm SmCO5 magnet was put into a cup yoke of 447J1 stainless steel and covered by 447J1 stainless steel disk yoke with a 316L stainless steel ring. To protect the magnet from corrosion, the connection was sealed by laser welding. The optimum dimensions were figured out by a finite element method. The performance of the magnetic attachment was investigated. As a result, a magnet device 4.4 mm in diameter and 2.1 mm in height was developed. The breakaway retention when the keeper touched it was 341 gf on average. (+info)
SmI2-promoted Reformatsky-type coupling reactions in exceptionally hindered contexts.
(38/98)
The use of chelated radionuclide (samarium-153-ethylenediaminetetramethylenephosphonate) to modulate phenotype of tumor cells and enhance T cell-mediated killing.
(39/98)
Fine synthetic nucleoside chemistry based on nucleoside natural products synthesis.
(40/98)
Synthetic nucleoside chemistry based on nucleoside natural products synthesis were described. First, a samarium diiodide (SmI 2)-promoted aldol reaction with the use of alpha-phenylthioketone as an enolate was developed. The characteristics of this reaction are that the enolate can be regioselectively generated and the aldol reaction proceeds under near neutral condition. This reaction is proved to be a powerful reaction for the synthesis of complex nucleoside natural products, and herbicidin B and fully protected tunicaminyluracil, which were undecose nucleoside natural products, were synthesized. Next, the synthetic methodology of the caprazamycins, which are promising antibacterial nucleoside natural products, was also developed by the strategy including beta-selective ribosylation without using a neighboring group participation. Our synthetic route provided a range of key analogues with partial structures to define the pharmacophore. Simplification of the caprazamycins was further pursued to develop diketopiperazine analogs. (+info)