Disease relevance of tantalum

• MATERIALS AND METHODS: In 289 patients, flexible tantalum stents were implanted in iliac artery stenoses (n - 223) or occlusions (n - 66) [1].
• Tantalum bronchography provides a good indication of the state of the bronchial tree at the time of death, and the changes seen are the result of both acute and chronic disease processes [2].
• Biomechanical and clinical evaluations of a porous tantalum implant for the treatment of early-stage osteonecrosis [3].
• In baboons, platelet thrombus formation on stainless steel and tantalum stents was equivalent and plateaued at approximately 2.5 x 10(9) platelets after 1 hour (p > 0.05) [4].
• METHODS: A total of 14 experimentally constructed aneurysms in dogs were treated with transfemorally placed balloon-expandable tantalum and self-expanding nitinol stents [5].

High impact information on tantalum

• NEs, manually isolated from Triturus cristatus oocytes, have been mounted on conductive silicon chips, fixed, critical point dried and coated with a thin, continuous film of chromium or tantalum and viewed at relatively high accelerating voltage in a field emission scanning electron microscope with the sample within the objective lens [6].
• METHODS AND RESULTS: Twenty-six adult male sheep underwent placement of 13 miniature tantalum markers into the LV epicardium and around the mitral annulus to allow calculation of LV volume and regional epicardial area [7].
• Paired comparison of vascular wall reactions to Palmaz stents, Strecker tantalum stents, and Wallstents in canine iliac and femoral arteries [8].
• METHODS AND RESULTS: Five closed-chest, autonomically blocked, sedated dogs were studied after placement of an LVAD (LV-femoral artery bypass), right coronary artery (RCA) occluder, and 27 miniature radiopaque tantalum markers into the LV and RV walls for independent computation of RV and LV volumes [9].
• Miniature radiopaque tantalum markers were implanted into the myocardium to measure LV volume [10].

Chemical compound and disease context of tantalum

• Miniature radiopaque tantalum markers were implanted into the myocardium to measure left ventricular volume, and biplane cinefluoroscopic images were obtained 1 week and 3 months after creation of mitral regurgitation [11].
• Results are reported for both ligation and aneurysm clips manufactured from three types of stainless steel as well as titanium, tantalum and niobium metals [12].
• We suspected a type 1 anaphylactic hypersensitivity to tantalum was present, but we have also considered that tantalum might have direct histamine releasing-like activity [13].
• Normal lungs from 15 children and adults dying without evidence of pulmonary disease were fixed and dried using a standardized technique and were radiographed after tantalum or silver nitrate bronchoacinography [14].

Biological context of tantalum

• Tiny radiopaque helices (0.85 times 1.5 mm) of pure tantalum wire were implanted by means of a simple insertor instrument into the left ventricular myocardium in 24 patients at the time of cardiac surgery [15].
• To determine the mechanism for the blood pressure increase, heart rate, blood pressure, and ventricular volumes (measured using fluoroscopy of tantalum midwall myocardial markers) were recorded before and after a 50% maximal voluntary contraction [16].
• We evaluated the accuracy of the non-imaging nuclear probe for measuring various parameters of left ventricular function by comparing these with simultaneous measurements acquired via tantalum marker cine-fluoroscopy [17].
• Tantalum inhalation and airway responses [18].
• Central and peripheral pulmonary mucociliary clearance was assessed by tantalum bronchography and serial chest roentgenograms in dogs [19].

Anatomical context of tantalum

• At operation seven miniature tantalum coils were placed into the midwall of the donor left ventricle so as to outline the ventricle in a 30 degrees right anterior oblique projection [20].
• Miniature tantalum myocardial markers were placed on the tip and base of each papillary muscle in six dogs [21].
• We have used such an instrument to visualise directly the structure of both cytoplasmic and nucleoplasmic surfaces of the NPC of manually isolated amphibian oocyte nuclear envelopes that have been spread, fixed, critical point dried and coated with a thin fine-grained film of chromium or tantalum [22].
• METHODS: Twelve specially constructed tantalum stents, 6 coated with polyetherurethane block copolymer and 6 uncoated, were overdilated by 25% in 12 normal renal arteries of six swine [23].
• A balloon expandable 2.0 mm tantalum Strecker stent was placed in the right carotid artery of 33 male New Zealand White rabbits after they had been fed a 0.5% cholesterol diet for 28 days [24].

Associations of tantalum with other chemical compounds

• In a porcine coronary model, fibrin film soaked for 3 h in heparin was used as a circumferential coating on a tantalum stent to assess the effect of this naturally occurring biopolymer on arterial healing [25].
• METHODS: A balloon-expandable tantalum stent was coated with silicon carbide to enhance thromboresistance (Tensum) [26].
• MATERIALS AND METHODS: By using an in vitro model, 14 stents-nine nitinol, one tantalum, two stainless steel, and two cobalt alloy-were investigated regarding their appearance at MR imaging [27].
• Natural history of pulmonary thromboemboli in dogs. Serial radiographic observation of clots labeled with powered tantalum [28].
• Under visible light irradiation (lambda = 420-500 nm), a tantalum oxynitride, TaON, functions as a stable and very efficient photocatalyst for oxidation of water into O2 with a sacrificial electron acceptor (Ag+) [29].

Gene context of tantalum

• Tantalum stents induce expression of GMP140 and GP53 on platelets after contact in an in vitro model [30].
• The inert metal tantalum oxide did not enhance HOS transformation frequency above untreated levels [31].
• Conversely, when the tantalum foil is placed medial to the caudal somites of an embryo having 21 somites (stage 14) or more, desmin is detected lateral to the barrier in most cases [32].
• In 15 human subjects, the vasa deferentia were occluded by applying two tantalum clips on one side and by conventional vasectomy with silk ligatures on the other [33].
• In whole blood collected in either heparin or ACD, a circle of platelets adheres to oxidized silicon, anodized tantalum, or glass; this circle is similar in size to the one of fibrinogen left by plasma [34].

Analytical, diagnostic and therapeutic context of tantalum

• After this, 3.5-mm tantalum stents were implanted in both arteries [35].
• Tantalum markers were implanted into the LV midwall in 15 transplant recipients to measure time-varying, three-dimensional chamber twist using computer-assisted analysis of biplane cinefluoroscopic images [36].
• To quantify the three-dimensional regional dynamics of the left ventricular (LV) midwall and the centroid and cross-sectional shape of the LV chamber in the transplanted human heart, 12 miniature radiopaque tantalum markers were implanted in the LV midwall of the donor heart at the time of cardiac transplantation in 15 patients [37].
• To demonstrate this twisting motion, 10 orthotopic human cardiac allograft recipients were studied with biplane cineradiography of tantalum helices implanted within the LV midwall at 12 specific sites [38].
• The preparations were then examined by freeze-fracture electron microscopy employing conventional platinum/carbon replicas or by means of a new technique using thin tantalum replicas [39].

References