Disease relevance of iridium

• PURPOSE: To determine if iridium implant (IM) and external-beam radiation therapy (EBRT) is better than standard EBRT in locally advanced prostate cancer [1].
• According to available data, the combination of lumpectomy, axillary node dissection, external beam radiotherapy and iridium implant constitutes an acceptable alternative to mastectomy as treatment for primary cancer of the breast [2].
• PURPOSE: To report an interim analysis of whether centered endovascular irradiation with the iridium 192 ((192)Ir) source immediately after percutaneous transluminal angioplasty (PTA) of de novo femoropopliteal stenoses lowers the restenosis rate [3].
• A patient with recurrent adenoid cystic carcinoma of the trachea was recently treated again by combined external irradiation and endotracheal brachytherapy with iridium 192 sources; the results were dramatic without significant normal tissue toxicity [4].
• Electrodeposited iridium oxide pH electrode for measurement of extracellular myocardial acidosis during acute ischemia [5].

High impact information on iridium

• Here we report direct observations of the structure of supported metal clusters consisting of four iridium atoms, and the identification of hydrocarbon ligands bound to them during propene hydrogenation [6].
• Osmium isotope and iridium analyses of whole-rock limestone indicate a coeval enhancement of one order of magnitude in the influx rate of cosmic dust [7].
• Editing the stereochemical elements in an iridium catalyst for enantioselective allylic amination [8].
• Although no effect was found in the case of tartrate, enantiomeric excess appeared in the crystallization of the cobalt and iridium complexes [9].
• Dimerization of alkynes promoted by a pincer-ligated iridium complex. C-C reductive elimination inhibited by steric crowding [10].

Chemical compound and disease context of iridium

• In four patients there was a transient increase in serum bilirubin during iridium treatment and, in two cases (14 per cent), this was associated with mild cholangitis [11].
• Postoperative levels of steroid hormones have been measured in lymph and blood of 28 patients undergoing iridium implants as part of conservative treatment for operable breast cancer [12].
• BACKGROUND: Exposure to platinum group elements (PGEs) - platinum (Pt), palladium (Pd), rhodium (Rh) and iridium (Ir) - may cause acute toxicity or hypersensitivity with respiratory symptoms, urticaria and (less frequently) contact dermatitis [13].
• RATIONALE AND OBJECTIVE: The authors assess the clinical efficacy of transvenous closure of patent ductus arteriosus (PDA) with a new plug consisting of Ivalon foam and a platinum/iridium frame with four aortic and two pulmonary nitinol struts [14].
• A further series of 64 patients with more extensive "intermediate" type adenocarcinoma of the lower third of the rectum selected on the basis of age and poor surgical risk were treated by external beam 60 Cobalt irradiation (30 Gy over 12 days) followed by intracavitary and 192 iridium inplant after a two month interval [15].

Biological context of iridium

• The nature of Dexter triplet energy transfer between bonded systems of a red phosphorescent iridium complex 13 and a conjugated polymer, polyfluorene, has been investigated in electrophosphorescent organic light-emitting diodes [16].
• Carbon-fluorine bond activation coupled with carbon-hydrogen bond formation alpha to iridium: kinetics, mechanism, and diastereoselectivity [17].
• Reductive alkylation of proteins using iridium catalyzed transfer hydrogenation [18].
• Efficient catalysis of Nazarov cyclization using a cationic iridium complex possessing adjacent labile coordination sites [19].
• gamma-Al(2)O(3)-supported Ir(4) and Ir(6) were prepared by decarbonylation of tetra- and hexanuclear iridium carbonyls, respectively, and compared as catalysts for ethene hydrogenation at atmospheric pressure and temperatures in the range 273-300 K [20].

Anatomical context of iridium

• A dose of 14 Gy was delivered to the adventitia by using an iridium 192 source [21].
• Optimized afterloading therapy of cervix carcinoma with the discontinuous movement of the iridium source [22].
• Salvage irradiation of oropharynx and mobile tongue about 192 iridium brachytherapy in Centre Alexis Vautrin [23].
• METHODS AND MATERIALS: Thirty-nine patients with anal canal cancers, stages T1-T4 N0-2 M0, were treated with split-course EBR (50-50.4 Gy) and a Iridium 192 ((192)Ir-) HDR boost (6 Gy) performed during the 1-2-week split [24].
• External radiation therapy and transcatheter iridium in the treatment of extrahepatic bile duct carcinoma [25].

Associations of iridium with other chemical compounds

• This work explores the potential of iridium complexes of the N-heterocyclic carbene oxazoline ligands 1 in asymmetric hydrogenations of arylalkenes [26].
• Well-defined chiral spiro iridium/phosphine-oxazoline cationic complexes for highly enantioselective hydrogenation of imines at ambient pressure [27].
• Isolation and crystal structure of a water-soluble iridium hydride: a robust and highly active catalyst for acid-catalyzed transfer hydrogenations of carbonyl compounds in acidic media [28].
• The rate of ethene hydrogenation on Ir(4) is typically several times greater than that on Ir(6) [20].
• Alkane C-H activation and catalysis by an O-donor ligated iridium complex [29].

Gene context of iridium

• The diffraction data of the recombinant p21 have been collected to 2.5 and 3.5 A resolution for the native crystal and two heavy atom derivatives of mercury and iridium [30].
• pH-selective synthesis and structures of alkynyl, acyl, and ketonyl intermediates in anti-Markovnikov and Markovnikov hydrations of a terminal alkyne with a water-soluble iridium aqua complex in water [31].
• These comprise bis-cyclometalated iridium units [Ir(ppy)(2)(acac)] or [Ir(btp)(2)(acac)] where ppy is 2-phenylpyridinato, btp is 2-(2'-benzo[b]thienyl)pyridinato, and acac is acetylacetonate [32].
• The cationic PNP-Ir(I)(cyclooctene) complex 1 (PNP = 2,6-bis-(di-tert-butyl phosphino methyl)pyridine) reacts with benzene at 25 degrees C to quantitatively yield the crystallographically characterized, square pyramidal, iridium phenyl hydride complex cis-(PNP)Ir(Ph)(H), 2, in which the hydride is trans to the vacant coordination site [33].
• METHODS: One hundred and six patients with T1-T2, N0-N1 breast cancers (108 breasts) have been treated with lumpectomy, external irradiation (45 Gy in 5 weeks), and a boost dose on the tumor bed with HDR iridium brachytherapy [34].

Analytical, diagnostic and therapeutic context of iridium

• The iridium anomaly at the Cretaceous-Tertiary (KT) boundary was discovered in the pelagic limestone sequence at Gubbio on the basis of 12 samples analyzed by neutron activation analysis (NAA) and was interpreted as indicating impact of a large extraterrestrial object at exactly the time of the KT mass extinction [35].
• Iridium wire radiotherapy for high bileduct carcinoma [36].
• An array of four 50 microns-diameter iridium microelectrodes was inserted beneath the dura in each cat [37].
• In the absence of immunotherapy, tumour recurrence was observed in 61% of animals within a 12-month follow-up period after treatment with surgery and iridium-based radiotherapy [38].
• Immediately following a conventional brachytherapy dose and removal of the iridium seeds the tumors were heated again in a second treatment [39].

References