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Kinetics and quantification of the sites of destruction of 111-Indium-oxine-labeled autologous platelets were investigated in eight patients with idiopathic thrombocytopenic purpura. The mean platelet count was 17 +/- 9 X 10(9)/liter; platelets were separated by differential centrifugation and labeled with 5.6 +/- 2.5 MBq 111In. Whole body and organ 111In-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 111In-radioactivity expressed as a percentage of whole body activity. Mean platelet survival was 49.5 +/- 29.6 hr and the survival curves were exponential. Equilibrium percentage organ 111In-radioactivity was (normal values in parentheses): spleen 33.7 +/- 8.8 (31.1 +/- 10.2); liver 16.1 +/- 9.5 (13.1 +/- 1.3); thorax 22.8 +/- 3.7 (28.2 +/- 5.6). Percentage organ 111In-activity at the time when labeled platelets had disappeared 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 bone marrow radioactivity. 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 111In-platelet sequestration was not predictive of response of glucocorticoid therapy or indicative of the necessity for splenectomy. Quantitative 111In-labeled autologous platelet kinetic studies provide a new tool for the investigation of platelet disorders.U

Once-daily trovafloxacin 200 mg was compared with high-dose amoxicillin, 1 g three times daily, given for 7 to 10 days. At end of treatment (day 10), the response was clinically successful (cure + improvement) in 93% of 152 clinically evaluable trovafloxacin patients and in 89% of 160 amoxicillin patients. At study end (day 35), respective rates were 91% and 81% (95% confidence interval: 1.6, 17.6; P=0.01). In evaluable patients with positive baseline radiographs, 93% of trovafloxacin and 88% of amoxicillin patients demonstrated radiological resolution at end of treatment. Streptococcus pneumoniae and Haemophilus influenzae eradication rates were comparable at end of treatment in both treatment groups, but at study end Streptococcus pneumoniae eradication rates were higher in trovafloxacin patients (100% vs 81%). At study end, all four trovafloxacin patients with baseline penicillin-resistant Streptococcus pneumoniae were clinically cured with pathogen eradication, whereas two of five amoxicillin patients with baseline penicillin-resistant Streptococcus pneumoniae were clinical failures with pathogen persistence. For patients in whom no pathogen was identified, trovafloxacin was significantly more effective at end of treatment (P=0.096) and study end (P=0.013). Treatment-related adverse events were comparable; the most common were headache, vomiting and dizziness in trovafloxacin patients, and diarrhoea. headache and abdominal pain in amoxicillin patients.

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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.