Kinetics And Sites Of Destruction Of Indium-111-Oxine Labelled Platelets In Immune Thrombocytopenic Purpura

1981 ◽  
Author(s):  
A duP Heyns ◽  
P N Badenhorst ◽  
M G Lötter ◽  
F de Kock ◽  
C Herbst ◽  
...  
Keyword(s):  
Imaging System ◽  
Kinetic Studies ◽  
Reticuloendothelial System ◽  
Whole Body ◽  
Computer Assisted ◽  
Scintillation Camera ◽  
Thrombocytopenic Purpura ◽  
Indium 111 ◽  
System Acquisition ◽  
In Parenthesis

Kinetics and quantification of the sites of destruction of In-111-oxine labelled autologous platelets was investigated in eight patients with idiopathic thrombocytopenic purpura. The mean platelet count was 17 9 × 109/l; platelets were separated by differential centrifugation and labelled with 5,6 ±2,5 MBq In-111. Whole body and organ In-111-platelet distribution was quantitated with a scintillation camera and a computer assisted imaging system acquisition matrix. Areas of interest were selected with the computer and organ In-111-radioactivity expressed as a percentage of whole body activity. Mean platelet survival was 49,5+29,6h, and the survival curves exponential. Equilibrium percentage organ In-111-radioactivity was (normal values in parenthesis): spleen 33,7±8,8 (31,1 ± 10,2); liver 16,1 ± 9,5 (13,1 ± 1,3); thorax 22,8 ± 3,7 (28,8 ± 5,6). Percentage organ In-111-activity at the time when labelled platelets had been removed from the circulation was: spleen 44,5 ± 16,4 (40 ± 16); liver 16,0 ± 11,5 (32,4 ± 7,2); thorax 19,7±6,0 (17,7 ± 10,3). Thorax activity corresponds to radioactivity in the bony cage of the thorax. Three patterns of platelet sequestration were evident. Three patients had mainly splenic sequestration; two, mainly hepatic sequestration; and three, diffuse reticuloendothelial system sequestration with a major component of platelets destroyed in the bone marrow. Splenectomy was performed in two patients. The pattern of In-111-platelet sequestration was not predictive of response to glucocorticoid therapy or indicative of the necessity for splenectomy. Quantitative In-111-labelled autologous platelet kinetic studies provide a new tool for the investigation of platelet disorders.

Kinetics, Redistribution And Fate Of Indium-111-Labelled-Platelets In Patients With Aortic Aneurysms

1981 ◽  
Author(s):  
A duP Heyns ◽  
M G Lötter ◽  
P N Badenhorst ◽  
F de Kock ◽  
H Pieters ◽  
...  
Keyword(s):  
Imaging System ◽  
Reticuloendothelial System ◽  
Aortic Aneurysms ◽  
Whole Body ◽  
Computer Assisted ◽  
Scintillation Camera ◽  
Normal Limits ◽  
Geometrical Mean ◽  
Indium 111

Platelets of 7 patients with abdominal aortic aneurysms were labelled with In-lll-oxine prior to surgery. The platelets were reinjected with the patient positioned under a scintillation camera with a computer assisted imaging system. Images were acquisitioned daily, areas of interest selected with the computer, organ radioactivity- quantitated with a geometrical mean method and expressed as a percentage of whole body radioactivity. Platelet survival (PS) in the circulation was determined, and disappearance curves fitted to a gamma function “multiple hit” model.Mean PS was shorthened to 143,2 ± 47h (normal 232<17); the dissappearance curves were exponential in all but the two patients who had PS within normal limits. The surgically removed aneurysms were dissected and radioactivity of different layers measured. In-111-activity was confined to the superficial layers of the aneurysm.These techniques allow quantitative studies of the in vivo distribution of labelled platelets. Platelets are deposited in the aneurysms, this shortens PS, the disappearance curves become exponential, and the major sites of deposition of In-111-activity are in the liver and spleen. This indicates that although platelets are damaged and deposited in the aneurysm, the reticuloendothelial system remains a major site of platelet sequestration.

scholarly journals Platelet turnover and kinetics in immune thrombocytopenic purpura: results with autologous 111In-labeled platelets and homologous 51Cr- labeled platelets differ

Blood ◽  
1986 ◽  
Vol 67 (1) ◽  
pp. 86-92 ◽  
Author(s):  
P Heyns A du ◽  
PN Badenhorst ◽  
MG Lotter ◽  
H Pieters ◽  
P Wessels ◽  
...  
Keyword(s):  
Immune Thrombocytopenic Purpura ◽  
Severe Disease ◽  
Reticuloendothelial System ◽  
Computer Assisted ◽  
Scintillation Camera ◽  
Antiplatelet Antibody ◽  
Thrombocytopenic Purpura ◽  
Computer Assisted Image ◽  
The Difference

Abstract Mean platelet survival and turnover were simultaneously determined with autologous 111In-labeled platelets (111In-AP) and homologous 51Cr- labeled platelets (51Cr-HP) in ten patients with chronic immune thrombocytopenic purpura (ITP). In vivo redistribution of the 111In-AP was quantitated with a scintillation camera and computer-assisted image analysis. The patients were divided into two groups: those with splenic platelet sequestration (spleen-liver 111In activity ratio greater than 1.4), and those with diffuse sequestration in the reticuloendothelial system. The latter patients had more severe ITP reflected by pronounced thrombocytopenia, decreased platelet turnover, and prominent early hepatic platelet sequestration. Mean platelet life span estimated with 51Cr-HP was consistently shorter than that of 111In-AP. Platelet turnover determined with 51Cr-HP was thus over-estimated. The difference in results with the two isotope labels was apparently due to greater in vivo elution of 51Cr. Although the limitations of the techniques should be taken into account, these findings indicate that platelet turnover is not always normal or increased in ITP, but is low in severe disease. We suggest that this may be ascribed to damage to megakaryocytes by antiplatelet antibody. The physical characteristics in 111In clearly make this radionuclide superior to 51Cr for the study of platelet kinetics in ITP.

THE EFFECT OF INTRAVENOUS IMMUNOGLOBULIN ON PLATELET KINETICS IN CHRONIC IMMUNE THROMBOCYTOPAENIC PURPURA (ITP)

1987 ◽  
Author(s):  
P N Badenhorst ◽  
H F Kotze ◽  
A duP Heyns ◽  
M G Lotter ◽  
P Wessels ◽  
...  
Keyword(s):  
Intravenous Immunoglobulin ◽  
Kinetic Studies ◽  
Ivig Therapy ◽  
Reticuloendothelial System ◽  
Computer Assisted ◽  
Scintillation Camera ◽  
Significant Difference ◽  
Before And After ◽  
High Doses

Most patients with ITP respond to high doses of intravenous immunoglobulin (IVIg) with a transient increase in platelet count. The effect of IVIg on platelet kinetics was studied in 5 patients with chronic ITP. Autologous platelets were labelled with In-111 and mean platelet lifespan (MPLS) calculated; in vivo distribution and sites of platelet sequestration were determined with a scintillation camera and computer assisted image analysis. The studies were performed before and after treatment with 2 g/kg Sandoglobulin. Two groups of patients were identified: those with a splenic platelet sequestration pattern (spleen-liver In-111-activity ratio >1.4) and those with diffuse sequestration of platelets in the reticuloendothelial system (RES).There was a significant difference in mean platelet counts before and after treatment (p<0.05). Patients with a splenic sequestration pattern responded better to IVIg: the MPLS lengthened and the high spleen-liver ratio decreased. In the diffuse RES sequestration pattern group, IVIg had almost no effect on platelet kinetics. We conclude that platelet kinetic studies identify a subgroup of patients with ITP who will respond to IVIg therapy.

scholarly journals Platelet turnover and kinetics in immune thrombocytopenic purpura: results with autologous 111In-labeled platelets and homologous 51Cr- labeled platelets differ

Blood ◽  
1986 ◽  
Vol 67 (1) ◽  
pp. 86-92
Author(s):  
P Heyns A du ◽  
PN Badenhorst ◽  
MG Lotter ◽  
H Pieters ◽  
P Wessels ◽  
...  
Keyword(s):  
Immune Thrombocytopenic Purpura ◽  
Severe Disease ◽  
Reticuloendothelial System ◽  
Computer Assisted ◽  
Scintillation Camera ◽  
Antiplatelet Antibody ◽  
Thrombocytopenic Purpura ◽  
Computer Assisted Image ◽  
The Difference

Mean platelet survival and turnover were simultaneously determined with autologous 111In-labeled platelets (111In-AP) and homologous 51Cr- labeled platelets (51Cr-HP) in ten patients with chronic immune thrombocytopenic purpura (ITP). In vivo redistribution of the 111In-AP was quantitated with a scintillation camera and computer-assisted image analysis. The patients were divided into two groups: those with splenic platelet sequestration (spleen-liver 111In activity ratio greater than 1.4), and those with diffuse sequestration in the reticuloendothelial system. The latter patients had more severe ITP reflected by pronounced thrombocytopenia, decreased platelet turnover, and prominent early hepatic platelet sequestration. Mean platelet life span estimated with 51Cr-HP was consistently shorter than that of 111In-AP. Platelet turnover determined with 51Cr-HP was thus over-estimated. The difference in results with the two isotope labels was apparently due to greater in vivo elution of 51Cr. Although the limitations of the techniques should be taken into account, these findings indicate that platelet turnover is not always normal or increased in ITP, but is low in severe disease. We suggest that this may be ascribed to damage to megakaryocytes by antiplatelet antibody. The physical characteristics in 111In clearly make this radionuclide superior to 51Cr for the study of platelet kinetics in ITP.

Kinetics and Fate of 111Indium-Oxine Labelled Blood Platelets in Asplenic Subjects

1980 ◽  
Vol 44 (02) ◽  
pp. 100-104 ◽  
Author(s):  
Anthon duP Heyns ◽  
Matthys G Lötter ◽  
Philip N Badenhorst ◽  
Otto van Reenen ◽  
Henry Pieters ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Blood Platelets ◽  
Normal Subjects ◽  
Lower Limbs ◽  
Whole Body ◽  
Computer Assisted ◽  
Scintillation Camera ◽  
Survival Curves ◽  
Platelet Recovery ◽  
Body Activity

SummaryThe survival, tissue distribution and fate of 111Indium-oxine labelled autologous platelets was studied in four asplenic subjects with serial blood sampling, scintillation camera and computer-assisted imaging. Mean 111In-platelet recovery in the circulation was 89 ± 13% (± 1 SD). Platelet survival curves fitted a linear function best and was 238 ± 41 h. The shape of the survival curves of normal and asplenic subjects differed: in the asplenic subjects the curve was linear whereas that of normal subjects was significantly more curvilinear if analyzed by least squares computer fitting to a gamma function. Early hepatic 111In-activity was significant and transient and ascribed to the "collection injury". As labelled platelets disappeared from the circulation, 111Inactivity in the liver increased progressively and linearly to reach 42.5 ± 14.1 % of whole body activity at 240 h. Radioactivity also accumulated in the bone marrow, but could not be demonstrated in the vasculature of the lower limbs. These results would indicate that in asplenic subjects the major sites of destruction of senescent platelets are the liver and bone marrow.

Kinetics and in Vivo Redistribution of 111Indium-Labelled Human Platelets after Intravenous Protamine Sulphate

1980 ◽  
Vol 44 (02) ◽  
pp. 065-068 ◽  
Author(s):  
A duP Heyns ◽  
M G Lötter ◽  
P N Badenhorst ◽  
H Kotze ◽  
F C Killian ◽  
...  
Keyword(s):  
Imaging System ◽  
Human Platelets ◽  
Computer Assisted ◽  
Scintillation Camera ◽  
Protamine Sulphate ◽  
Normal Volunteers ◽  
Activated Platelets ◽  
Platelet Survival ◽  
Platelet Aggregates

SummaryThe pathogenesis of thrombocytopenia induced by intravenous protamine sulphate was studied in six patients who underwent cardiopulmonary bypass surgery, and in three normal volunteers. Autologous platelets were labelled with 111Indium-oxine. Platelet lifespan was determined. In vivo 111In-platelet localization, organ redistribution and sites of destruction were quantitated with a scintillation camera and a computer-assisted imaging system. Protamine induced a transient thrombocytopenia, maximal 5-10 min after injection, and 30-40 min in duration. The thrombocytopenia was accompanied by a transient accumulation of platelets in the liver. The splenic platelet pool remained unaltered and no platelets accumulated in the lungs. Platelet survival, measured in two volunteers, was slightly longer than normal and fitted a linear function best. There was a severe transient neutropenia during the period of thrombocytopenia. We conclude that protamineinduced thrombocytopenia is caused by hepatic accumulation of "activated" platelets or platelet aggregates, the process is reversible, and in the two normal volunteers studied, platelet survival was not affected.

Tc-99m Labeled Complexes of Aldehydes and Glutamate as Cholescintigraphic Agents

1975 ◽  
Vol 14 (04) ◽  
pp. 330-338
Author(s):  
L. G. Colombetti ◽  
J. S. Arnold ◽  
W. E. Barnes
Keyword(s):  
Nuclear Medicine ◽  
Gall Bladder ◽  
Rose Bengal ◽  
Valence State ◽  
Monosodium Glutamate ◽  
Kinetic Studies ◽  
Scintillation Camera ◽  
Blood Clearance ◽  
Lower Valence ◽  
Wire Basket

SummaryTc-99m pyridoxylidene glutamate has proven to be an excellent biliary scanning agent, far superior in many respect to the commonly used 1-131 rose bengal. The preparation of the compound as previously reported by Baker et al is too time consuming and requires the use of an autoclave which is not available in most nuclear medicine departments. In our facility, we have been preparing similar compounds using several aldehydes and monosodium glutamate to make labeled complexes having the same pharmacological characteristics. The mixture of monosodium glutamate, aldehyde, and Tc-99m pertechnetate is made slightly alkaline, purged with helium, and placed in a sealed vial. The vial, which is protected by a wire basket, is then heated in a laboratory oven at 130° C for a period of 15 to 20 minutes. During this time, the technetium is reduced to a lower valence state and bound to the complex formed. Chromatographic data show that these compounds are chemically similar to that previously reported. The compounds prepared concentrate in the gall bladder of the rabbit in less than 10 minutes. Kinetic studies have been performed on dogs with a scintillation camera and small digital computer to measure rates of blood clearance, liver and gall bladder uptake, and excretion into the intestine. The aldehyde — glutamate complex promises to be a useful scanning agent for the diagnosis of biliary and hepatocellular diseases.

Preparation of a Viable Population of Indium-111- Labelled Human Blood Platelets

1979 ◽  
Vol 42 (05) ◽  
pp. 1473-1482 ◽  
Author(s):  
A Dup Heyns ◽  
P N Badenhorst ◽  
H Pieters ◽  
M G Lötter ◽  
P C Minnaar ◽  
...  
Keyword(s):  
Platelet Rich Plasma ◽  
Blood Platelets ◽  
Kinetic Studies ◽  
Physiological Saline ◽  
Human Platelets ◽  
Autologous Plasma ◽  
Platelet Suspension ◽  
Viable Population ◽  
Indium 111

SummaryFactors influencing labelling of human platelets with 111Indium-8-hydroxyquinoline ([111In]-oxine) in a physiological saline medium were investigated. The efficiency of labelling is influenced by time of incubation, concentration of oxine, and pH of the incubating medium. It was found that a viable platelet population could be labelled under the following conditions: (1) centrifugation of platelet rich plasma in polystyrene conical tubes at 800 g for 15 min; (2) resuspension of the platelet pellet in saline, pH 5.5; (3) incubating for 30 min at 22°C with [111In]-oxine at a concentration of 6.25 mg oxine/litre platelet suspension; (4) washing once with platelet poor autologous plasma (PPP); and (5) finally resuspending the platelets in PPP. The labelled platelets aggregated normally with collagen and ADP. Electron microscopy, done immediately after labelling, showed internal organelle reorganization characteristic of activated platelets. These ultrastructural features were reversible on incubation in PPP at 37°C for 30 min. The 111In is not released from aggregated platelets and the label does not elute from incubated platelets for at least five hr. We conclude that human platelets thus labelled are suitable for in vivo kinetic studies.

scholarly journals Labeling of Salmonella Typhymurium with iodine-131 to study phagocytic function in rats

1989 ◽  
Vol 31 (3) ◽  
pp. 135-138
Author(s):  
Maria K. Sato ◽  
Aldo J. Rodrigues Junior ◽  
Edwaldo E. Camargo
Keyword(s):  
Whole Body ◽  
Large Field ◽  
Scintillation Camera ◽  
Functional Evaluation ◽  
Body Images ◽  
System A ◽  
Carrier Free ◽  
Free Iodine ◽  
Iodine 131 ◽  
Reticulo Endothelial System

The present study describes a method for labeling Salmonella typhymurium with iodine-131 to evaluate both the morphological and the functional characteristics of the reticulo-endothelial system. A suspension containing 2 x 10(9) bacteria per ml was labeled with carrier-free Na131I without reductor, with a labeling yield of 46.5 ± 3% and 3.5 ± 1.3% of free Iodine-131. The biodistribution of the labeled bacteria in rats was studied with a large field-of-view scintillation camera equiped with a pinhole collimator. Whole body images were obtained 15 and 30 minutes after intravenous injection of the labeled microorganisms. Images showed accumulation of bacteria in the liver and both normal and transplanted spleens of the animals. Autoradiographs of liver and spleen demonstrated labeled bacteria within the cells of the reticulo-endothelial system. The method described is easy to perform, has a good labeling yield and allows the functional evaluation of the reticulo-monophagocytic system, including transplanted spleens.

Changes in regulation of human zinc metabolism with age

1992 ◽  
Vol 263 (5) ◽  
pp. R1162-R1168 ◽  
Author(s):  
M. E. Wastney ◽  
S. Ahmed ◽  
R. I. Henkin
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Zinc Concentration ◽  
Kinetic Studies ◽  
Compartmental Analysis ◽  
Whole Body ◽  
Zinc Metabolism ◽  
Zinc Release ◽  
Urinary Zinc Excretion ◽  
Using Data

To assess changes in zinc metabolism with age, kinetic studies were performed in healthy adults (26 men, 21 women) aged 20-84 yr after a single oral or intravenous bolus of 65Zn. Studies covered two consecutive 9-mo periods while subjects were on a basal dietary intake of approximately 10 mg Zn/day and while taking an additional 100 mg Zn/day orally. Zinc metabolism was analyzed by compartmental analysis using data from plasma, red blood cells, urine, feces, liver, thigh, and whole body [M. E. Wastney, R. L. Aamodt, W. F. Rumble, and R. I. Henkin. Am. J. Physiol. 251 (Regulatory Integrative Comp. Physiol. 20): R398-R408, 1986]. Changes in observed and model calculated values of zinc metabolism were assessed on age by regression. During basal state, zinc release from red blood cells decreased with age. During zinc loading, response (defined as change from basal state) of plasma zinc concentration, urinary zinc excretion, and liver zinc increased with age, while response of fraction of zinc taken up by red blood cells decreased with age. In men, response of amount of zinc absorbed increased with age and in women response of fraction of endogenous zinc excreted decreased with age. Four responses that changed with age (urinary excretion, red blood cell exchange, absorption, and endogenous excretion) occurred at previously defined sites of regulation of zinc metabolism. Results show that regulation of zinc metabolism changes with age.

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