| 1. |
- 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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| 2. |
- Carlsson, Goran, et al.
(författare)
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The effect of total body microwave hyperthermia and hepatic artery ligation on liver tumors—an experimental study in rats
- 1983
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Ingår i: Journal of Surgical Oncology. - : Wiley. - 0022-4790 .- 1096-9098. ; 22:1, s. 37-40
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Tidskriftsartikel (refereegranskat)abstract
- The effect of general microwave hyperthermia and hepatic artery ligation (HAL) was tested on Wistar rats with a transplanted N‐methyl‐N‐nitroso‐guanidine‐induced adenocarcinoma in the liver. Total body hyperthermia (41.5°C for 1 hour, three times during 24 hours) was given on the same day as HAL, and 1, 2, and 3 days after. HAL induced a slower tumor growth than untreated controls. No additive effect was registered when total body microwave hyperthermia was added to HAL. When hyperthermia was added 2 days after HAL, there was a transient decrease in tumor volume as in the HAL series. Total body microwave hyperthermia added 3 days after HAL induced a faster tumor growth than after HAL alone. When hyperthermia was added the same day and 1 day after HAL, there was a 50% mortality.
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| 3. |
- Darte, Lennart, et al.
(författare)
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Quality control of 99mTc-radiopharmaceuticals - Evaluation of GCS minicolumns in routine clinical work with scintillation cameras
- 1980
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Ingår i: European Journal Of Nuclear Medicine. - 0340-6997. ; 5:6, s. 521-527
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Tidskriftsartikel (refereegranskat)abstract
- Gel chromatography column scanning (GCS) is a rapid and reliable method for the quality control of 99mTc-radiopharmaceuticals. With this method the labelled compound and various impurities such as free pertechnetate, hydrolyzed reduced technetium or other 99mTc-complexes are obtained in one testing procedure. Using minicolumns results can be obtained with a simple testing procedure within a few minutes after the sample is taken; this is significant in routine radiopharmaceutical work. The resolution of the recording system is important, so as to be able to utilize fully the good separation ability of the minicolumn. Minicolumns were studied with some commonly used radiopharmaceuticals. A scintillation camera was used to record minicolumn data under various conditions and the results were compared to those obtained using a scanner to reveal optimal recording conditions for the scintillation camera.
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| 4. |
- Hafström, Larsolof, et al.
(författare)
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Influence of vasoactive drugs on blood flow in subcutaneous tumors – an experimental study in rats
- 1980
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Ingår i: Journal of Surgical Oncology. - : Wiley. - 0022-4790 .- 1096-9098. ; 14:4, s. 359-366
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Tidskriftsartikel (refereegranskat)abstract
- Subcutaneously implanted tumors in Wistar and Lister rats were used as a model for the study of metastatic tumor blood flow and how it is affected by vasoactive drugs. Blood flow measurements were obtained using the labelled microsphere method and the reference organ technique. Microspheres (15‐μm) labelled with either 99Tcm or 51 Cr isotopes were injected intracardially and a reference sample was drawn simultaneously at constant speed. This was performed before and after the infusion of vasoactive drugs, and (as control), saline infusion. The drugs tested (adrenaline, noradrenaline, glucagon, histamine, and vasopressin) showed profound effects on central hemodynamic parameters and on muscle and skin blood flow. The relative tumor blood flow, measured as the ratio between tumor and skin or tumor and muscle blood flow, was calculated. The results show that no enhancement of the relative tumor blood flow could be registered. In fact, a decrease in the tumor‐to‐muscle‐blood‐flow ratio was noted when noradrenaline was infused, and in the tumor‐to‐skin ratio when adrenaline was infused. Blood flow in subcutaneous tumors was four to five times that in muscle or skin. Tumor blood flow was also inversely related to the size of the tumor.
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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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