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PubMed1989

Treatment of liver tumors with yttrium-90 microspheres alone.

Fifteen patients with liver metastases and one patient with hepatoma were treated by infusing 15 microns diameter plastic microspheres containing yttrium-90 into the hepatic artery. Twenty additional patients were screened but were found to be unsuitable for treatment. Follow-up angiography was done in 13 of the 16 treated patients. In five patients there was a reduction in tumor volume by more than 50% and in another two patients there was a smaller reduction. In six patients gastritis or gastric ulceration occurred and in three this was demonstrated to be due to unintended infusion of microspheres into the gastric circulation. For patients treated with yttrium-90 microspheres, mean survival time after referral was 62 weeks and in the untreated group it was 30 weeks, although this difference was not significant. We conclude that yttrium-90 microspheres alone can effect reduction in the size of liver tumors in some patients in whom their use is feasible.

Follow-Up Studies↗
PubMed1989

Comparative biodistributions of yttrium- and indium-labeled monoclonal antibody B72.3 in athymic mice bearing human colon carcinoma xenografts.

The biodistribution of yttrium- and indium-labeled monoclonal antibody (MAb) B72.3 IgG using three different chelate conjugates (SCN-Bz-EDTA, CA-DTPA, and SCN-Bz-DTPA) was compared in athymic mice bearing LS-174T tumors. The 88Y-SCN-Bz-DTPA-B72.3 yielded 40% ID/g at 5-7 days in the tumors, while the 88Y-SCN-Bz-EDTA-B72.3 and 88Y-CA-DTPA-B72.3 showed only 6-8% ID/g. The yttrium uptake in the bone with the SCN-Bz-EDTA and CA-DTPA conjugated IgG was over 14 and 11% ID/g, respectively, while 88Y-SCN-Bz-DTPA-B72.3 showed only 3% ID/g. In contrast, the 111In-labeled B72.3 uptake in the bone with all three chelate conjugates was 2-3% ID/g. The differences in yttrium- versus indium-labeled MAb biodistributions demonstrate the difficulty in using 111In-labeled MAbs to predict the biodistribution and dosimetry of 90Y-labeled MAbs unless chelate conjugates such as SCN-Bz-DTPA are used.

Animals↗
PubMed1986

[Changing of organ distribution of radioactive yttrium in rats by varying amounts of carrier].

There is little change in the organ distribution of yttrium citrate complex after addition of 0.01 mg/kg BW as carrier. Adding increasing amounts of inactive yttrium up to 1 mg/kg BW caused a considerable reduction in bone uptake and an increasing accumulation in the liver and spleen by transformation to colloid. Uptake in the lung indicates formation of macro-particles. The transformation into colloid can be varied by changing the citrate concentration. The 90Y-citrate complex for therapy should be used either without or with very little carrier of inactive yttrium.

Animals↗
PubMedDate not supplied

[The effect of yttrium-90 radio synovectomy on the intra-articular xenon-133 clearance in rheumatic joint diseases].

Nine inflamed knee joints out of eight patients were examined before and after intraarticular injection of yttrium-90 silicate colloid, in order to find out the effect of radiation synovectomy on the perfusion of the joints. These joints and the untreated contralateral knee joints were examined as to the clinical status and the fast component Tf of the xenon-133 clearance was determined as a means of the perfusion of the synovium. A linear correlation exists between the clinical status of the knee joint and the perfusion as determined by Tf measured three months before and after injection of yttrium-90. Also the joints without any radiation synovectomy showed this correlation. Three months after radiation synovectomy with yttrium-90 there was still no therapeutic effect apparent in the majority of the inflamed knee joints (seven out of nine). At this stage there still existed a hyperaemia. Therefore, it seems that on the whole three months are too short a period to judge the therapeutic effect.

Adult↗
PubMed1998

Evaluation of the in vivo biodistribution of yttrium-labeled isomers of CHX-DTPA-conjugated monoclonal antibodies.

UNLABELLED: We evaluated the in vivo stability and biodistribution of four isomers (CHX-A', CHA-A", CHX-B' and CHX-B") of 2-(p-isothiocyanatobenzyl)-cyclohexyl-diethylenetriaminepentaaceti c acid (CHX-DTPA), a recently developed backbone-substituted derivative of DTPA. METHODS: The ligands were conjugated to monoclonal antibody B3, a murine IgG1 kappa, and labeled with 88Y at 55.5-66.6 MBq/mg (1.5-1.8 mCi/mg). Nontumor-bearing nude mice were injected intravenously with 55.5-66.6 kBq (1.5-1.8 microCi) of 88Y-labeled B3 conjugates and with 125I-labeled B3 as an internal control. The mice were then killed at 6, 24, 48, 96 and 168 hr postinjection. RESULTS: At 168 hr, the concentration of 88Y in processed bone of either CHX-A' [4.6% injected dose (ID)/g] or CHX-A" (4.0%ID/g) was less than that of either the CHX-B' (21.9%ID/g) or B" (12.1%ID/g) ligands. The two ligands CHX-B" and CHX-B' were not acceptable for yttrium labeling of antibody because of their high and progressive bone accumulation. The accumulation of 88Y in bone of CHX-B' was five times greater than that of CHX-A' at 168 hr. The CHX-A" cleared from the circulation slightly faster than CHX-A' without releasing the yttrium and showed the lowest uptake by bone of any of the four isomers. The accumulation in the other normal organs was similar for all four isomers of 88Y-CHX-B3 conjugates. CONCLUSION: Although the CHX-B" and CHX-B' were not acceptable for labeling with yttrium, the CHX-A' and CHX-A" were suitable, indicating that differences in stereochemistry can greatly influence stability of radionuclide in the chelate.

Animals↗
PubMed1985

Histologic changes in rat brain tissue caused by neodymium-yttrium aluminum garnet laser irradiation. II. Cerebellum.

Histologic changes after neodymium-yttrium aluminum garnet laser irradiation were evaluated in the rat cerebellum. Irradiation of 60 W (corresponds to 45.2 W/mm2) to the posterior fossa was dangerous even in adult rats, although this value was safe for the rat cerebral hemisphere as previously reported. The histologic changes caused by neodymium-yttrium aluminum garnet laser irradiation were similar to those caused by thermal energies. To the adult rat cerebellum, 45 W (35.2 W/mm2) can safely be applied. For the further use of the neodymium-yttrium aluminum garnet laser in neurosurgery, our findings should be taken into consideration.

Animals↗
PubMed2004

Neodymium:yttrium-aluminum-garnet laser arteriotomy with embolectomy for central retinal artery occlusion.

PURPOSE: To describe a patient with central retinal artery occlusion successfully treated with neodymium:yttrium-aluminum-garnet laser arteriotomy and embolectomy. DESIGN: Interventional case report. METHODS: A 77-year-old woman noted sudden loss of vision after vigorous coughing. A central retinal artery occlusion was diagnosed. Four hours after symptoms appeared, arteriotomy and embolectomy with neodymium:yttrium-aluminum-garnet laser was performed. RESULTS: Displacement of embolus outside the artery with return of retinal perfusion and recovery of vision. Laser treatment also resulted in vitreous hemorrhage and false aneurysm formation of the central retinal artery. CONCLUSIONS: Neodymium:yttrium-aluminum-garnet laser arteriotomy in a patient with central retinal artery occlusion resulted in extrusion of the embolus, reopening of the central retinal artery, and return of vision. This technique warrants further study as a primary treatment for this blinding disorder.

Aged↗
PubMed1995

Video-assisted thoracic surgical resection with the neodymium:yttrium-aluminum-garnet laser.

Since January 1991, we have performed 79 video-assisted neodymium: yttrium-aluminum-garnet laser resections for pulmonary nodular or interstitial disease. Pathologic examination demonstrated malignancy in 59 patients (32 primary and 27 metastatic), benign nodules in 11, interstitial processes in seven, and granulomatous disease in two. There were 39 men and 40 women with a mean age of 63.4 +/- 12.5 years. Thirty-nine patients underwent resection with the neodymium:yttrium-aluminum-garnet laser alone and 40 had lesions resected with a combination of laser and endoscopic stapling. Laser excision was performed for lesions deep in the substance of the lung or on its effaced surface; both are locations that make stapling alone difficult. Fifteen of 32 patients with a diagnosis of primary lung malignancy underwent open anatomic resections. Pulmonary reserves of the other 17 patients were inadequate for further resection. Operative time, duration of chest tube placement, length of hospital stay, and complication rate were compared with those for 72 patients undergoing video-assisted thoracic surgical resection of nodules with staplers alone. Although operative time for laser-assisted procedures was longer (p < 0.05), there were no differences in duration of chest tube placement or hospital stay compared with stapled resections. The complication rate for laser-treated cases was not higher than for stapled resections and consisted primarily of air leaks lasting 2 to 7 days. The neodymium:yttrium-aluminum-garnet laser is a safe and precise primary or adjunctive tool for video-assisted thoracic surgical pulmonary resection.

Adult↗
PubMed2000

Quantitative Imaging of Yttrium-86 with PET. The Occurrence and Correction of Anomalous Apparent Activity in High Density Regions.

Purpose: Yttrium-86 has been proposed for use as a quantitative positron emission tomography imaging agent to determine the in vivo distribution of therapeutic pharmaceuticals labeled with yttrium-90, a pure beta minus emitter. This study identifies, and proposes a solution for, an artifact, which interferes with quantitation.Procedures: Yttrium-86 is a 14.7-hour halflife positron emitter (33% abundance) with multiple high energy gamma rays in cascade. Phantom measurements with a GE Advance PET scanner using standard attenuation and scatter corrections, demonstrated anomalous apparent activity in inactive higher density regions.Results: Apparent activity up to 30% of the surrounding true activity was observed in a bone equivalent material. Even higher activities were observed if the scatter correction was omitted. This phenomenon was determined to result from the effect of attenuation correction on true coincidences between one gamma ray and a second gamma ray or annihilation photon.Conclusion: A simple additional correction based on sinogram tail subtraction improves accuracy significantly.

Journal Article↗
PubMed2005

New synthetic approach to yttrium hydroxoacetates, structural characterization, and use as a precursor for coated conductors.

A novel synthetic approach is given for the preparation of a metal-organic lanthanide sol-gel precursor solution and its application for the production of coated conductors. Besides all other problems concerning the technical process itself, the key to a successful deposition of oxide layers is the choice of the precursor solution and the understanding of the mechanism of deposition. Moreover, the isolation and characterization of the species involved in the reaction is very important. Regarding the complex process occurring during the formation of the surface layer, it is obvious that the best choice should have a compound already containing the final composition of the layer. Two compounds of composition [Y(OAc)3(H2O)2]2 and [Y(OAc)3]2(H2O) were isolated from their precursor solution and characterized by X-ray structural analysis. A short outlook will give an insight into the possible bonding mechanisms of the surface layer. These experiments were made with the mixed metal-oxide system yttrium-stabilized zirconium oxide, which is widely used as a substrate for superconducting oxides. A study of the structure of hydrated yttrium acetates, by single-crystal X-ray diffraction, infrared spectra, and elemental analysis demonstrates that there are two separate structures for hydrated yttrium acetates, which play a role as an intermediate in the building of ceramic oxide layers for coated conductors.

Journal Article↗
PubMed1996

A Proposal for Positive Cooperativity in Anion-Cation Binding in Yttrium and Lutetium Complexes Based on o-Amino-Substituted Phenolate Ligands. On the Way to Coordination Polymers by Self-Assembly. Molecular Structures of [ClLu(OAr)(3)Na] (X-ray) and [ClY(OAr')(3)Y(OAr')(3)Na] (X-ray and (89)Y-NMR).

Unique hetero(poly)metallic complexes [ClM(OAr)(3)Na] (M = Lu (3a), Y (3b)) and [ClY(OAr')(3)Y(OAr')(3)Na] (4) containing the bis (OAr = OC(6)H(2)(CH(2)NMe(2))(2)-2,6-Me-4) and mono (OAr' = OC(6)H(4)(CH(2)NMe(2))-2) o-amino-substituted phenolate ligands have been synthesized and characterized by NMR ((1)H, (13)C, and (89)Y) and X-ray structure determinations (3a and 4). Crystals of 3a are triclinic, space group P&onemacr;, with unit cell dimensions a = 10.706(1) Å, b = 14.099(2) Å, c = 18.882(3) Å, alpha = 93.48(1) degrees, beta = 99.49(1) degrees, gamma = 108.72(11) degrees, and Z = 2. The chlorine, lutetium, and sodium atoms in 3a lie on a pseudo-3-fold axis ( angleCl-Lu.Na = 177.82(5) degrees ) around which the three phenolate ligands are arranged in such a way that a "propeller-like" molecule with screw-type chirality results. Crystals of 4 are triclinic, space group P1, with unit cell dimensions a = 11.411(4) Å, b = 13.325(4) Å, c = 13.599(4) Å, alpha = 88.91(3) degrees, beta = 65.44(2) degrees, gamma = 72.77(3) degrees, and Z = 1. In 4 the chlorine, the two yttrium and the sodium atoms lie on a pseudo-3-fold axis (Cl-Y(1).Y(2).Na: angleCl-Y.Y = 179.36(8) degrees and angleY.Y.Na = 178.38(10) degrees ) around which the six phenolate ligands are arranged in two shells of three ligands. One shell bridges the yttrium atoms in an asymmetric fashion, while the second shell bridges the second yttrium and the sodium atom, resulting in two shells of opposite screw-type chirality. (1)H, (13)C, and (89)Y (for 3b and 4) NMR confirmed that the structures found for 3a and 4 in the solid state are retained in solution. For 4 (89)Y NMR showed two separate resonances (202.4 and 132.4 ppm), with (2)J(YY) = 0.4 Hz. The formation of 3a and 3b is described as resulting from positive cooperativity in anion-cation bonding: coordination of chloride anion to a neutral metal tris(phenolate) leads to preorganization of available binding sites in the resulting anionic complex for the binding of the sodium cation. In 4 this cooperativity is the driving force for the self-assembly of an anionic bimetallic molecular structure with available, preorganized binding sites for the capture of the cation. A proposal is made to use these observations for the possible synthesis of new coordination polymers.

Journal Article↗
PubMed1999

Synthesis, Structure, and Molecular Orbital Studies of Yttrium, Erbium, and Lutetium Complexes Bearing eta(2)-Pyrazolato Ligands: Development of a New Class of Precursors for Doping Semiconductors.

Treatment of yttrium metal with bis(pentafluorophenyl)mercury (1.5 equiv), 3,5-di-tert-butylpyrazole (3 equiv), and pyridine (2 equiv) in toluene at ambient temperature for 120 h afforded tris(3,5-di-tert-butylpyrazolato)bis(pyridine)yttrium(III) (33%). In an analogous procedure, the reaction of erbium metal with 3,5-dialkylpyrazole (alkyl = methyl or tert-butyl), bis(pentafluorophenyl)mercury, and a neutral nitrogen donor (4-tert-butylpyridine, pyridine, n-butylimidazole, or 3,5-di-tert-butylpyrazole) yielded tris(3,5-di-tert-butylpyrazolato)bis(4-tert-butylpyridine)erbium(III) (63%), tris(3,5-di-tert-butylpyrazolato)bis(pyridine)erbium(III) (88%), tris(3,5-di-tert-butylpyrazolato)bis(n-butylimidazole)erbium(III) (48%), tris(3,5-dimethylpyrazolato)bis(4-tert-butylpyridine)erbium(III) (50%), and tris(3,5-di-tert-butylpyrazolato)(3,5-di-tert-butylpyrazole)erbium(III) (59%), respectively. Treatment of tris(cyclopentadienyl)lutetium(III) or tris(cyclopentadienyl)erbium(III) with 3,5-di-tert-butylpyrazole (3 equiv) and 4-tert-butylpyridine (2 equiv) in toluene at ambient temperature for 24 h afforded tris(3,5-di-tert-butylpyrazolato)bis(4-tert-butylpyridine)lutetium(III) (83%) and tris(3,5-di-tert-butylpyrazolato)bis(4-tert-butylpyridine)erbium(III) (41%), respectively. The X-ray crystal structures of all new complexes were determined. The X-ray structure analyses revealed seven- and eight-coordinate lanthanide complexes with all-nitrogen coordination spheres and eta(2)-pyrazolato ligands. Molecular orbital calculations were carried out on dichloro(pyrazolato)diammineyttrium(III). The calculations demonstrate that eta(2)-bonding of the pyrazolato ligand is favored over the eta(1)-bonding mode and give insight into the bonding between yttrium and the pyrazolato ligands. Complexes bearing 3,5-di-tert-butylpyrazolato ligands can be obtained in a high state of purity and sublime without decomposition (150 degrees C, 0.1 mmHg). Application of these complexes as source compounds for chemical vapor deposition processes is discussed.

Journal Article↗
PubMed2005

Effect of OH- on the luminescent efficiency and lifetime of Tb3+-doped yttrium orthophosphate synthesized by solution precipitation.

In this work, we use the solution precipitation method to synthesize Tb3+-doped yttrium orthophosphate, which is a green-emission luminescent material. The evolution of hydrated yttrium orthophosphate (YPO4.2H2O) to dehydrated yttrium orthophosphate (YPO4) is observed in the heat-treatment process, simultaneously, accompanying the structural transformation from monoclinic churchite-type to tetragonal xenotime-type structure. Furthermore, the luminescent efficiency of Tb3+-doped YPO4 presents a sharp jump at a critical temperature in this heat-treatment process. Interestingly, this critical temperature is close to the structural transformation temperature. The remarkable change of luminescent efficiency seems to be related to the structural transformation. However, the FTIR and fluorescent decay measurements at 10 and 300 K indicate that the OH group is the origin of luminescent efficiency change. OH- ions with high vibration frequency provide an efficient means to quench the luminescence. The comparison of the luminescent efficiency, OH- content, and lifetime of 5D4 of Tb3+ between two samples with the same crystal structure proves that the structural transformation has no significant effect on the luminescent efficiency and lifetime. On the basis of these results, it is proposed that correctly preventing OH- ions inside the host matrix or effectively eliminating them may improve the luminescent efficiency greatly. This idea also may be applied to other optical systems.

Journal Article↗
PubMed2004

Yttrium complexes incorporating the chelating diamides [ArN(CH2)xNAr]2- (Ar = C6H3-2,6-iPr2, x= 2, 3) and their unusual reaction with phenylsilane.

Novel yttrium chelating diamide complexes [(Y[ArN(CH(2))(x)NAr](Z)(THF)(n))(y)] (Z = I, CH(SiMe(3))(2), CH(2)Ph, H, N(SiMe(3))(2), OC(6)H(3)-2,6-(t)Bu(2)-4-Me; x = 2, 3; n = 1 or 2; y = 1 or 2) were made via salt metathesis of the potassium diamides (x = 3 (3), x = 2 (4)) and yttrium triiodide in THF (5,10), followed by salt metathesis with the appropriate potassium salt (6-9, 11-13, 15) and further reaction with molecular hydrogen (14). 6 and 11(Z = CH(SiMe(3))(2), x = 2, 3) underwent unprecedented exchange of yttrium for silicon on reaction with phenylsilane to yield (Si[ArN(CH(2))(x)NAr]PhH) (x = 2 (16), 3) and (Si[CH(SiMe(3))(2)]PhH(2)).

Journal Article↗
PubMed1984

Intra-articular radioactive yttrium and triamcinolone hexacetonide: an inconclusive trial. Arthritis and Rheumatism Council Multicentre Radiosynoviorthesis Trial Group.

A restricted sequential design multicentre controlled trial of yttrium-90 against triamcinolone intra-articularly was undertaken in patients with rheumatoid arthritis with knee involvement. The trial had to be discontinued because of dwindling recruitment over time. The reasons for this and other features contributing to an inconclusive outcome are noted. This experience lends little encouragement to the idea that yttrium-90 therapy is more or less advantageous than triamcinolone hexacetonide.

Arthritis, Rheumatoid↗
PubMed1988

Effects of hepatic arterial yttrium 90 glass microspheres in dogs.

A 22-micron glass microsphere called TheraSphere (Theragenics Corp., Atlanta, GA) has been developed in which yttrium 89 oxide is incorporated into the glass matrix and is activated by neutron bombardment to form the beta-emitting isotope yttrium 90 (Y 90) before using the spheres as radiotherapeutic vehicles. The injection of up to 12 times (on a liver weight basis) the anticipated human dose of nonradioactive TheraSphere into the hepatic arteries of dogs was well tolerated and produced clinically silent alterations within centrolobular areas. The hepatic arterial (HA) injection of radioactive TheraSphere also produced portal changes similar to those observed in humans after external beam therapy. While the extent of damage increased with the delivered dose, radiation exposures in excess of 30,000 cGy did not cause total hepatic necrosis and were compatible with survival. No microspheres distributed to the bone marrow and absolutely no myelosuppression was encountered in any animal. Proposed hepatic exposures to humans of 5000 to 10,000 cGy by means of these microspheres, therefore, would appear to be feasible and tolerable. Radiotherapeutic microsphere administration preceded by regional infusion of a radiosensitizing agent and/or immediately following the redistribution of blood flow toward intrahepatic tumor by vasoactive agents can potentially yield a synergistic, highly selective attack on tumors confined to the liver.

Animals↗
PubMed2002

Hydroxylapatite with substituted magnesium, zinc, cadmium, and yttrium. I. Structure and microstructure.

Hydroxylapatite (HA) was made containing magnesium, zinc, cadmium, and yttrium. Salts of these cations were added to precipitating HA; the precipitates were dried and sintered at 1100 degrees C for 1 h. Lattice parameters from X-ray diffraction spectra showed that these elements were incorporated into the apatite structure at a level of 2% added fraction of calcium in HA and up to 7% for yttrium. The densities of different substituted apatites were close to theoretical for pressed and sintered samples, which is evidence for low bulk porosity. The grain sizes of substituted apatites were smaller than those of pure HA except for cadmium-containing apatite. Surfaces of etched samples showed no second phases, whereas surfaces of unetched samples showed second phases and higher porosity than etched surfaces.

Biocompatible Materials↗
PubMed1993

Metabolism and toxicity of intravenously injected yttrium chloride in rats.

Although radioactive yttrium (Y) has been used for medical treatment, little attention has been directed toward the toxicity of Y. We report time-course and dose-related changes in tissue distribution, subcellular localization, clearance, and acute toxicity of iv-injected yttrium chloride (YCl3) in rats. Intravenously injected Y was predominantly distributed to plasma in the blood. At doses more than 0.2 mg Y/rat, most plasma Y appears to be in colloidal material which was composed of proteins and some minerals. Electron microscopic analyses revealed that the colloidal material was taken up by phagocytic cells in the liver and spleen. The liver Y was slowly cleared with a half-time of 144 days at a dose of 1 mg Y/rat. Glutamic-oxaloacetic and glutamic-pyruvate transaminase activities in blood plasma were increased with a peak at 20 hr postinjection at a dose of 1 mg Y/rat and returned to their control values at 170 hr postinjection, indicating that iv-injected YCl3 caused acute hepatic injury. Some of the plasma Ca was translocated to the colloidal material and plasma Ca concentration was increased transiently following injection of YCl3, probably because of resorption of bone. At a dose of 1 mg Y/rat, a significant and tremendous amount of Ca was deposited in the liver (over 10-fold) and spleen (over 100-fold), while Ca concentration was only slightly increased in the lung and kidney (less than 1.5-fold). These results indicate that the liver and spleen are primary target organs of iv-injected YCl3.

Animals↗