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- Bergqvist, Lennart, et al.
(författare)
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Particle sizing and biokinetics of interstitiallymphoscintigraphic agents
- 1983
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Ingår i: Seminars in Nuclear Medicine. - 0001-2998. ; 13:1, s. 9-19
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Tidskriftsartikel (refereegranskat)abstract
- The biokinetics of inert lymphoscintigraphic agentsstrongly depends on their particle size. Different techniques for characterization of colloids are discussed. Experiments have been performed on eight different colloids. The particle size has been investigated with scanning electron microscopy. Activity distributions have been obtained with ultrafiltration and gel-column scanning technique. The colloids suggested for lymphoscintigraphy were found to have a median size of about 40-50 nm except one minimicro-aggregated human serum albumin colloid which has a median particle size around 10 nm. The biokinetics were studied with a scintillation camera in rabbits after a subcutaneous injection. Timeactivity curves were generated. After 5 hr the rabbits were dissected and the activity content in different tissues measured. A compartment model for the biokinetics was designed and rate constants evaluated. The total and specific activity uptake in parasternal lymph nodes was highest for the small-particle colloids. The compartment model showed a good fitting to the experimental data.
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| 5. |
- Rydén, Stefan, et al.
(författare)
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A scintillation camera technique for measurements of the reticuloendothelial function -Comparison of different methods for measuring RES function
- 1982
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Ingår i: European Journal Of Nuclear Medicine. - 0340-6997. ; 7, s. 16-21
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Tidskriftsartikel (refereegranskat)abstract
- A highly standardized 99mTc-sulphur colloid was used to evaluate reticuloendothelial system (RES)-function in the normal rat and after RE blockade by gelatin (Haemaccel). Activity distribution in the animals was measured with a scintillation camera technique. Total uptake of activity in the liver was estimated. From the time-activity curves over the liver, the phagocytic index (kphag) was evaluated. Estimation of the uptake rate of the labelled colloid into the liver and into other parts of the RES was also performed using a twocompartment model. Different methods of evaluation of RE function were compared. It was shown that for a proper estimation of the RE function, the whole uptake curve must be considered. Gelatin (Haemaccel) significantly reduced the total colloid uptake by the liver. The colloid uptake rate into the liver was also significantly reduced. Liver specimens after colloid injection were examined by light and electron microscopy showing vacuolation of hepatocytes and sinusoidal cells probably due to pinocytosis. The technique described enables functional studies of the RES. It has the advantage of noninvasive registrations and is based on the same technical facilities as used for routine liver scintigraphy.
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| 6. |
- Thörne, Johan, et al.
(författare)
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An experimental method for in vivo studies of pulmonary platelet sequestration
- 1984
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - 1619-7070. ; 9:10, s. 472-477
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Tidskriftsartikel (refereegranskat)abstract
- It has been reported in earlier in vitro studies that soft tissue trauma and endotoxin-induced shock causes pulmonary platelet trapping (PPT). This paper describes a noninvasive in vivo technique for dynamic studies of PPT in rabbits. Autologous platelets were labeled with 111In and reinfused into the animals. The following day, the rabbits were anesthetized and placed in a supine position under a scintillation camera. Continuous measurement of the activity distribution in the animal was performed for 35 min. The first 5 min represented a preshock measurement, whereafter endotoxin E. coli was injected IV. The following 2-3 min showed a sudden increase of radioactivity in the lungs indicating PPT, and thereafter a slow decrease to almost the preshock level. A simultaneous decrease in the number of platelets and the radioactivity in peripheral blood also indicated the induction of PPT. This study clearly shows that PPT can be detected in vivo with an easy, noninvasive scintillation camera method
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