131 Matching Results

Search Results

Advanced search parameters have been applied.

New technetium-99m generator technologies utilizing polyethylene glycol-based aqueous biphasic systems

Description: Two new schemes for TcO{sub 4}{sup {minus}}/MoO{sub 4}{sup 2{minus}} separations from OH{sup {minus}} and MoO{sub 4}{sup 2{minus}} media using polyethylene glycol (PEG)-based aqueous biphasic systems (ABS) have been developed. The two most important salt solutions in current {sup 99m}Tc-generator technologies, OH{sup {minus}} and MoO{sub 4}{sup 2{minus}}, also salt out PEG to form ABS. In liquid/liquid PEG- ABS, pertechnetate can be separated from molybdate with separation factors as high as 10,000. Stripping is accomplished by reduction of the TcO{sub 4}{sup {minus}} and back extraction into a salt solution. the strip solution can be the salt of an imaging agent (e.g., Na{sub 4}HEDPA) and thus may, under the appropriate conditions, be injected directly into the human body. {sup 99m}TcO{sub 4}{sup {minus}} can also be concentrated from a dilute load solution of {sup 99}MoO{sub 4}{sup 2{minus}} in NaOH using an aqueous biphasic extraction chromatographic technique (ABEC). A rinse with K{sub 2}CO{sub 3} assures that all {sup 99}MoO{sub 4}{sup 2{minus}} is removed from the column and this is confirmed by a rapid drop in {sup 99}Mo activity by the fourth free column volume (fcv) of rinse. The {sup 99m}TcO{sub 4}{sup {minus}} is then eluted with water. This chromatographic separation affords 94% of the {sup 99m}TcO{sub 4}{sup {minus}} activity in 5 fcv, with the y spectrum showing less than 2 {times} 10{sup {minus}4} of the original {sup 99}Mo activity.
Date: December 31, 1995
Creator: Rogers, R.D.; Bond, A.H.; Zhang, Jianhua & Horwitz, P.
Partner: UNT Libraries Government Documents Department

Development of more efficacious Tc-99m organ imaging agents for use in nuclear medicine by characterization of radiopharmaceuticals. Final report, September 1, 1992--June 30, 1998

Description: The primary goals of this project were twofold: (1) Development of a microsensor that would demonstrate the capability for in vivo monitoring of a radiopharmaceutical after its injection into a test animal; and (2) Exploration of capillary electrophoresis (CE) as a separation technique for the analysis of radiopharmaceuticals that are mixtures of different compounds. The combination of in vivo sensors for real-time monitoring of specific chemical states of a radiopharmaceutical in individual organs and CE for analysis of radiopharmaceuticals prior to injection would provide valuable information regarding the fate of an imaging agent after administration. Such information should give insight into strategies for the development of more efficacious radiopharmaceuticals.
Date: August 4, 1998
Creator: Heineman, W.R. & Seliskar, C.J.
Partner: UNT Libraries Government Documents Department

Experiments with neutron-rich isomeric beams

Description: A review of experimental results obtained on microsecond-isomeric states in neutron-rich nuclei produced in fragmentation reactions and studied with SISSI-Alpha-LISE3 spectrometer system at GANIL Caen is given. The perspectives of experiments based on secondary reactions with isomeric beams are presented.
Date: January 1, 1998
Creator: Rykaczewski, K.; Grzywacz, R.; Lewitowicz, M.; Pfuetzner, M. & Grawe, H.
Partner: UNT Libraries Government Documents Department

Use of a new tandem cation/anion exchange system with clinical-scale generators provides high specific volume solutions of technetium-99m and rhenium-188

Description: In this paper the authors describe the first application of a simple and inexpensive post elution tandem cation-anion exchange column system which is based on generator elution with salts of weak acids such as ammonium acetate instead of saline solution to provide very high specific volume solutions of technetium-99m and rhenium-188 from clinical scale molybdenum-99/technetium-99m generator prepared from low specific activity (n,y) molybdenum-99, and tungsten-188/rhenium-188 generators, respectively. Initial passage of the bolus through a strong cation exchange cartridge converts the ammonium acetate to acetic acid which is essentially not ionized at the acidic pH, allowing specific subsequent amine type (QMA SepPak{trademark}) anion exchange cartridge column trapping of the microscopic levels of the pertechnetate or perrhenate. Subsequent elution of the anion cartridge with a small volume (< 1 mL) of saline then provides high specific volume solutions of technetium-99m by concentration of the high eluant volumes obtained by elution of clinical-scale (1 Ci) generators. This new approach also works very effectively to obtain high specific volume solutions of rhenium-188 (> 500 mCi/mL) from the alumina-based tungsten-188/rhenium-188 generator.
Date: March 1, 1998
Creator: Knapp, F.R. Jr.; Beets, A.L.; Mirzadeh, S. & Guhlke, S.
Partner: UNT Libraries Government Documents Department

Recent advances in technetium-99m radiopharmaceuticals

Description: From 11th international annual meeting of the German Society of Nuclear Medicine; Athens, Greece (24 Sep 1973). The development of a number of new technetium-99m-labeled radiopharmaceuticals for use in scintiscanning is described. The effectiveness of colloids, chelates, and complexes that localize in a variety of body organs is discussed. The use of /sup 99m/Tc-labeled red blood cells for cardiovascular diagnostics is discussed. (CH)
Date: January 1, 1973
Creator: Richards, P. & Smith, T.D.
Partner: UNT Libraries Government Documents Department

Comparative evaluation of $sup 123$I and /sup 99m/Tc for thyroid studies

Description: A comparative study of the metabolism of /sup 129/I and /sup 99m/Tc in the thyroid was made. Thirty-minute uptake curves were determined for 26 patients and comparison images were obtained at 30 minutes With /sup 99m/Tc and at 30 minutes and 24 hours with /sup 123/I. Both radionuclides can be used to advantage in assessing thyroid function and anatomy. The reasonable cost of /sup 123/I adds to its clinical value. (HLW)
Date: January 1, 1973
Creator: Atkins, H.L.; Ansari, A.N.; Bradley-Moore, P.R.; Lambrecht, R. & Wolf, A.
Partner: UNT Libraries Government Documents Department

Doses to the hand during the administration of radiolabeled antibodies containing Y-90, Tc-99m, I-131, and Lu-177

Description: Exposure of the hands of medical personnel administering radiolabeled antibodies (RABs) was evaluated on the basis of (a) observing and photo-documenting administration techniques, and (b) experimental data on doses to thermoluminescent dosimeters (TLDs) on fingers of phantom hands holding syringes, and on syringes, with radionuclides in the syringes in each case. Actual exposure data for I-131 and Lu-177 were obtained in field studies. Variations in handling and administration techniques were identified. Dose rates measured using TLDs on the surface of loaded syringes were adjusted for differences in electronic stopping power, absorption coefficients, and attenuation between dosimeters and tissue to estimate dose-to-skin averaged over 1 cm{sup 2} at 7 mg cm{sup {minus}2} depth for Y-90, Tc-99m, I-131, and Lu-177. Dose rate coefficients to the skin, if in contact with the syringe wall, were 89, 1.9, 3.8, and 0.41 {micro}Sv s{sup {minus}1} per 37 MBq (1 mCi) for Y-90, Tc-99m, I-131, and Lu-177, respectively. For dose reduction, when using Y-90 the importance was clearly indicated of (a) avoiding direct contact with syringes containing RABs, if practical, and (b) using a beta-particle shield on the syringe. In using a syringe for injection, doses can best be approximated for the geometry studied by (a) wearing a finger dosimeter on the middle finger, toward the outside of the hand, on the hand operating the plunger, and (b) wearing finger dosimeters on the inner (palm) side of the finger on the hand that supports the syringe for energetic beta-particle emitters, such as Y-90 and Re-188.
Date: February 1997
Creator: Barber, D. E.; Carsten, A. L.; Kaurin, D. G. L. & Baum, J. W.
Partner: UNT Libraries Government Documents Department

[Research programs in radiotherapy]. DOE final report, 1996

Description: Results which have not yet been published in detail are reported here on the following associated studies: Progress in the area of macrocyclic chelates for targeted therapy; Progress in biologic activation with radioimmunoconjugate therapy: Association of molecular receptor increase and tumor response in ChL6/L6 protocol patients; Progress in genetically engineered Lym-1 single chain molecules; Progress in analysis of molecular genetic coded messages to enhance tumor response; Progress on development and validation of planar imaging for therapy planning systems; Progress in development of a 3-D treatment planning system using SPECT; Progress in development of methods to evaluate enhancement of tumor penetration in a murine model; and Progress in clinical applications.
Date: December 31, 1996
Creator: DeNardo, S.J.
Partner: UNT Libraries Government Documents Department

Nuclear structure considerations for gamma-ray lasers

Description: Presented are initial results in our investigation of the nuclear physics issues of gamma-ray lasers. These include the questions of what is known from existing experimental data, where does one optimally search for nuclei displaying simultaneously both closely lying levels and nuclear isomerism, and which theoretical models does one employ for systematic searches for candidate nuclei and for calculation of detailed candidate level properties.
Date: January 1, 1985
Creator: Strottman, D.; Arthur, E.D. & Madland, D.G.
Partner: UNT Libraries Government Documents Department

Technetium Behavior and Recovery in Soil

Description: Technetium-99 in soils is of great concern because of its long half-life and because it can not be detected readily. This work reviews the behavior of technetium in various types of soils. A method for extracting technetium from soil was developed with the use of technetium-95m and 99m to determine recoveries at each step. Technetium chemistry is very complicated and problem areas in the behavior and recovery have been highlighted. Technetium is widely used in nuclear medicine and a review of its chemistry pertaining to radiopharmaceuticals is relevant and helpful in environmental studies. The technetium behavior in the patented citric acid method for the removal of toxic metals in contaminated soils was studied. An innovative method using solid phase extraction media for the concentration of technetium extracted from soils, with water and hydrogen peroxide, was developed. This technique may have a useful environmental application for this type of remediation of technetium from contaminated soils.
Date: December 1, 1995
Creator: Meinken,G.E.
Partner: UNT Libraries Government Documents Department

Chemistry of technetium as it is applied to radiopharmaceuticals

Description: The chemistry of /sup 99m/Tc, used as a tracer in medicine, is discussed. Study of the chemistry of this element should lead to a better understanding of the use of radiopharmaceuticals that contain it and to a more rapid development of additional useful formulations. The mechanism of labeling human serum albumin with /sup 99m/Tc is discussed. (LK)
Date: January 1, 1973
Creator: Richards, P. & Steigman, J.
Partner: UNT Libraries Government Documents Department

Labeling of blood cells with /sup 99m/Tc

Description: Erythrocytes, leukocytes, and tumor cells were labeled with /sup 99m/Tc to take advantage of the ideal physical properties of /sup 99m/Tc. Clinical studies indicate that labeled erythrocytes can be used to obtain improved vascular and splenic imaging as well as reliable red cell volumes. The erythrocytes have been labeled with and without the use of an added reducing agent. Two methods of adding the reducing agent stannous chloride have been proposed which differ in the order of addition of the stannous ion and the pertechnetate. The preliminary reports of labeling of leukocytes and tumor cells offer hope that further development will result in truly specific radiopharmaceuticals. (auth)
Date: January 1, 1974
Creator: Eckelman, W.C.; Smith, T.D. & Richards, P.
Partner: UNT Libraries Government Documents Department

Response of the mouse fetus to radiation from Na/sup 99m/TcO$sub 4$

Description: The element technetium has recently assumed ecological importance as a source of low-level radiation, with the use of /sup 99m/Tc in nuclear medicine and production of /sup 99m/Tc during generation of electricity by nuclear reaction. When technetium is introduced as pertechnetate into the blood stream of pregnant females, it is transported across the placental barrier to the fetus, where a portion appears to be incorporated into biomolecules. When combined as biomolecules, radionuclides that decay by electron capture or isomeric transition show a lethality greater than that predicted in cell cultures and radiation therapy. The decay of /sup 99m/Tc by isomeric transition, together with the other considerations, places a high priority on the investigation of its radiation effects due to clinical doses of up to 25 mCi. Female mice were given daily i.v. injections of 0, 5, 50, and 500 $mu$ Ci of /sup 99m/Tc as pertechnetate in isotonic saline throughout gestation, gestation and lactation, or lactation. At two months of age, the progeny were mated with randomly selected litter mates to produce a second generation; the process was repeated with their progeny for production of the third generation.Preliminary results reinforce the existing concern about use of /sup 99m/Tc-pertechnetate in pregnant or potentially pregnant subjects. (auth)
Date: January 1, 1975
Creator: Lathrop, K.A.; Gloria, I.V. & Harper, P.V.
Partner: UNT Libraries Government Documents Department

Acquisition, processing and display of gated cardiac scintigrams

Description: An improved method for non-traumatic and essentially noninvasive evaluation of left ventricular (LV) function with /sup 99m/Tc as the tracer was developed. This method combines previously used EKG gating techniques for cardiac blood pool visualization with new computerized acquisition, processing and display techniques. An Anger camera, a small computer, and a physiological synchronizer are used to acquire a sequence of eight scintigrams which span the entire cardiac cycle. Under our present protocol two twenty-minute sequences are obtained, one an LAO (50$sup 0$) projection, the other an RAO (30$sup 0$) projection. Subsequently these images are processed on-line with a digital filter to increase definition of the cardiac borders. The eight images are then displayed sequentially on a specially designed electronic monitor to give an impression of the beating heart somewhat analogous to that obtained with invasive contrast angiography. (auth)
Date: January 1, 1974
Creator: Alpert, N. M.; Chesler, D. A.; McKusick, K. A.; Potsaid, M. S.; Pohost, G. M. & Dinsmore, R. A.
Partner: UNT Libraries Government Documents Department

Feasibility study of medical isotope production at Sandia National Laboratories

Description: In late 1994, Sandia National Laboratories in Albuquerque, New Mexico, (SNL/NM), was instructed by the Department of Energy (DOE) Isotope Production and Distribution Program (IPDP) to examine the feasibility of producing medically useful radioisotopes using the Annular Core Research Reactor (ACRR) and the Hot Cell Facility (HCF). Los Alamos National Laboratory (LANL) would be expected to supply the targets to be irradiated in the ACRR. The intent of DOE would be to provide a capability to satisfy the North American health care system demand for {sup 99}Mo, the parent of {sup 99m}Tc, in the event of an interruption in the current Canadian supply. {sup 99m}Tc is used in 70 to 80% of all nuclear medicine procedures in the US. The goal of the SNL/NM study effort is to determine the physical plant capability, infrastructure, and staffing necessary to meet the North American need for {sup 99}Mo and to identify and examine all issues with potential for environmental impact.
Date: December 1, 1995
Creator: Massey, C.D.; Miller, D.L. & Carson, S.D.
Partner: UNT Libraries Government Documents Department

Laboratory studies of radionuclide transport in fractured Climax granite

Description: This report documents our laboratory studies of radionuclide transport in fractured granite cores. To simulate natural conditions, our laboratory studies used naturally fractured cores and natural ground water from the Climax Granite Stock at the Nevada Test Site. For comparison, additional tests used artificially fractured granite cores or distilled water. Relative to the flow of tritiated water, {sup 85}Sr and /sup 95m/Tc showed little or no retardation, whereas {sup 137}Cs was retarded. After the transport runs the cores retained varying amounts of the injected radionuclides along the fracture. Autoradiography revealed some correlation between sorption and the fracture fill material. Strontium and cesium retention increased when the change was made from natural ground water to distilled water. Artificial fractures retained less {sup 137}Cs than most natural fractures. Estimated fracture apertures from 18 to 60 {mu}m and hydraulic conductivities from 1.7 to 26 x 10{sup -3} m/s were calculated from the core measurements.
Date: June 1, 1982
Creator: Failor, R.; Isherwood, D.; Raber, E. & Vandergraaf, T.
Partner: UNT Libraries Government Documents Department