The use of 185 MBq and 740 MBq of 153-samarium hydroxyapatite for knee synovectomy in haemophilia.

The penetration of beta energy of 153-samarium ((153) Sm) (0.8 MeV) is not only appropriate for synovectomy of median articulations but is possible to improve the radiobiological effect using increased activities. The aim of this study was to assess the effectiveness of 185 MBq and 740 MBq of 153-samarium hydroxyapatite ((153) Sm-HA) in knees of haemophilic patients. Thirty-one patients--36 knees, 30 males, were divided into two groups without coinjection of corticosteroid: A - 14 patients (17 knees) treated with intra-articular dose of 185 MBq of (153) Sm-HA, average age 23 years; B--17 patients (19 knees) with 740 MBq of (153) Sm-HA, average age 21.3 years. The evaluation before and after 1 year of synovectomy used the following criteria: reduction in the number of haemarthroses and use of the coagulation factor and improvement in articular motility. Adverse-effects occurrence was considered too. Early and late scintigraphic studies were performed after synoviorthesis and no joint immobilization was recommended. The reduction in haemarthrosis and use of coagulation factor were: group 1--31.3% and 25%; group 2--81.5% and 79% with P < 0.001 respectively; no significant improvement in knees motility was noted for both groups. Four cases of mild reactional synovitis were observed in each group. The scintigraphic control showed homogenous distribution of the radiopharmaceuticals with no articular escape; the material was considered safe by its permanence in the articulation. We have significant improvement in the synovectomy of haemophilic knees with 740 MBq of (153) Sm-HA; the less penetration of its beta radiation was compensated by the increased biological effect with the higher used activity.

(67)Ga and (68)Ga purification studies: preliminary results.

The positron emission tomography technique is very useful for diagnosis of several diseases. (68)Ga is a positron emitter with half-life of 67.7 min. As it is available from (68)Ge/(68)Ga generator systems, it is not necessary to have a nearby cyclotron. However, the eluate from commercial generators contains high levels of metallic impurities, which compete with (68)Ga in biomolecular labeling. Thus, a subsequent purification step is needed after generator elution. Here we present the results of two different methods developed for handmade purification of (68)Ga and (67)Ga for subsequent radiolabeling of biomolecules. Two purification methods were employed. The first one uses a cation exchange resin, and (68)Ga is eluted with a solution of acetone/acid. The second method of purification is performed by column chromatography solvent extraction, with (68)Ga recovery in deionized water. The best result was achieved with cationic resin AG50W-X8 (>400 mesh). However, the resin is not commercially available. The extraction chromatography column based on absorption of diisopropyl ether in XAD-16 is the most promising purification method. Although the levels of (68)Ga recovery and purification were smaller with the cationic resin method, its advantage is the (68)Ga recovery in deionized water.

In vivo comparative study of hydroxyapatite labeled with different radioisotopes: evaluation of the scintigraphic images.

Radyosinovectomy (RSV) is a radiotherapeutic modality where a beta-emitting radionuclide is administered locally by intra-articular injection on the form of a colloid or radiolabeled particulate. RSV is a well-accepted therapeutic procedure in inflammatory joint diseases and has been successfully employed for more than 50 years as a viable alternative to surgical and chemical synovectomy. The aim of this work is to compare the in vivo stability of hydroxyapatite labelled with (177)Lu, (90)Y and (153)Sm. All radionuclides were labelled with high yield and were retained in the joint for 7 days, showing stability and usefulness as tools in the RSV treatment. A similar retention of the products in the muscle was observed when the particles were administrated in the muscle. However, the pure form of the radionuclides were rapidly cleared from the blood and accumulated in the liver when injected i.v.. Although (153)Sm-HA is already available for nuclear medicine procedures and clinical studies with (90)Y-HA have been developed, (177)Lu-labeled RSV agents will be economically more viable and has not been studied yet. Its favorable characteristics contribute to follow, to predict and asses the success of RSV by bone scintigraphy studies.

[Early release of the antiinflammatory cytokine IL-10 in traumatic brain injury]. / Liberación precoz de la citokina antiinflamatoria IL10 en el trauma severo de cráneo.

It has been reported that upwards of 50% of patients who survive an initial brain traumatic insult subsequently die due to infection and multiple organ failure. A paralysis of cell-mediated immunity following trauma, partially induced by anti-inflammatory cytokine release, appears to be responsible for the increased susceptibility to infections. We determined the plasma levels of the anti-inflammatory cytokine IL-10 and the pro-inflammatory TNF-alpha in 15 patients admitted with severe traumatic brain injury (TBI). None of the patients had received glucocorticoid or catecholamine treatment. Thirteen volunteers served as controls. At study entry the IL-10 plasma levels were significantly higher than in controls: 41.8 (17.3-265.4) pg/mL vs. 2.2 (1.4-2.7) pg/mL, p < 0.001 (Mann-Whitney test). There was no difference between the first (at study entry) and second sample (4 hours later) (Wilcoxon test). TNF-alpha plasma levels were similar in patients and controls at study entry and 4 hours later. We conclude that severe TBI patients present an early response, with a significant increase of IL-10 plasma levels. These results could partially explain the immunodepression following TBI.

Liberación precoz de la citokina antiinflamatoria IL10 en el trauma severo de cráneo. / [Early release of the antiinflammatory cytokine IL-10 in traumatic brain injury]

It has been reported that upwards of 50

of patients who survive an initial brain traumatic insult subsequently die due to infection and multiple organ failure. A paralysis of cell-mediated immunity following trauma, partially induced by anti-inflammatory cytokine release, appears to be responsible for the increased susceptibility to infections. We determined the plasma levels of the anti-inflammatory cytokine IL-10 and the pro-inflammatory TNF-alpha in 15 patients admitted with severe traumatic brain injury (TBI). None of the patients had received glucocorticoid or catecholamine treatment. Thirteen volunteers served as controls. At study entry the IL-10 plasma levels were significantly higher than in controls: 41.8 (17.3-265.4) pg/mL vs. 2.2 (1.4-2.7) pg/mL, p < 0.001 (Mann-Whitney test). There was no difference between the first (at study entry) and second sample (4 hours later) (Wilcoxon test). TNF-alpha plasma levels were similar in patients and controls at study entry and 4 hours later. We conclude that severe TBI patients present an early response, with a significant increase of IL-10 plasma levels. These results could partially explain the immunodepression following TBI.