The beneficial effect of a beta-D-xyloside, Iliparcil, in the prevention of postthrombolytic rethrombosis in the rat.

The effect of Iliparcil, a new orally active beta-D-xyloside venous antithrombotic, was studied on the rethrombosis following thrombolytic therapy in rats, using a modified Umetsu model. The drug was administered by oral route prior to thrombolytic therapy, which consisted of administering a combination of heparin and urokinase (H/U) at 37.5 and 70,000 IU/kg, respectively. Time to reocclusion increased from 3.9 min with saline to 10.5 min following H/U injection. When Iliparcil (30 mg/kg, oral route) was administered 4 h before H/U injection, the time to reocclusion was increased by 250% compared with H/U alone (p < 0.001). Similarly, dermatan sulfate (DS), administered intravenously (3 mg/kg) 5 min before thrombus induction, also increased the time to reocclusion (300% compared with H/U alone; p < 0.001). It was also shown that times to reocclusion following Iliparcil or DS treatments were still increased even when heparin dosage was decreased. These results suggest that an antithrombotic product derived from the beta-D-xyloside family could be advantageously used in combination with thrombolytic treatment instead of heparin, which causes complications and side effects.     

Lack of correlation between in vivo peroxidatic activity patterns and tumoricidal activity in vitro of peritoneal macrophages after intraperitoneal immunization with tumor cells

Immunization of C57BL mice with one inoculum of 10(7) DBA/2-derived SL2 lymphosarcoma cells resulted in a +/- 20-fold increase in the total number of peritoneal cells. The number of macrophages showed a 10-fold increase from 3 x 10(6) (control mice) to 3.4 x 10(7) cells at day 8 after immunization. Within this macrophage population, four different cell types, based on the ultrastructural peroxidatic activity patterns, could be distinguished: exudate macrophages, resident macrophages, resident-exudate macrophages and peroxidatic-activity-negative macrophages. The number of exudate macrophages significantly increased in the peritoneal cavity after immunization: at day 8 after immunization, a peak value of 10(7) cells was observed. At the same time, there were 2.2 x 10(7) peroxidase-activity-negative macrophages present (representing the control value x 50). Significant in vitro tumoricidal activity of the isolated macrophages could not be measured until 8 days after immunization. At that time, a cytotoxicity index of 68 was reached. After immunization of the C57BL mice with 3 injections with allogeneic SL2 cells, there were no dramatic changes in the number of peritoneal cells after the last immunization. Only immediately after the last immunization was a minor increase in peroxidatic-activity-negative macrophages seen. But already at 5 days after the last immunization, the composition of the peritoneal suspension was similar to that of non-immunized mice with predominantly resident macrophages. The cytotoxicity of the peritoneal macrophages from hyperimmunized mice was constantly high during 1-15 days after the last immunization (cytotoxicity index ranged from 66-72). In order to study which type(s) of macrophage(s) (resident, exudate, resident-exudate or peroxidatic-activity-negative) is/are responsible for the cytotoxicity measured in vitro, peritoneal cell suspensions (obtained after immunization) were fractionated according to their affinity to wheat germ agglutinin (WGA) coupled to Sepharose columns. Comparison of the values of cytotoxicity measured before and after separation into "subtypes" of the macrophages revealed that the expression of cytotoxicity is not correlated with any of the "sub-types", especially when the peroxidatic activity pattern is is taken as a criterion.     

Comparative study of rest technetium-99m sestamibi SPET and low-dose dobutamine stress echocardiography for the early assessment of myocardial viability after acute myocardial infarction: importance of the severity of the infarct-related stenosis

Rest technetium-99m sestamibi single-photon emission tomography (SPET) has been shown to under-estimate viability in some patients with chronic ischaemic myocardial dysfunction. The present study was designed to appraise the value of^99mTc-sestamibi as a viability tracer in patients with a recent myocardial infarction and to determine factors that might influence its accuracy in assessing infarct size. Therefore, rest^99mTc-sestamibi SPET, low-dose dobutamines stress echocardiography and quantitative coronary angiography were performed in 51 patients with a recent myocardial infarction. Perfusion activity and regional wall motion were scored semi-quantitatively using the same segmental division of the left ventricle. Assessment of^99mTc-sestamibi uptake as a marker of viability was performed by comparing a binary uptake score (viable=>50% vs necrotic =50% of the maximal tracer activity) with a binary wall motion classification during low-dose dobutamine infusion (viable=normal/hypokinetic vs necrotic=akinetic/dyskinetic). Infarct size, expressed as the number of segments with evidence of necrotic tissue, was significantly greater in the scintigraphic study than in the echocardiographic study (2.8±1.5 vs 2.2±1.3,P=0.006). This overestimation of infarct size by^99mTc-sestamibi was present only in patients with a severe infarct-related stenosis (% diameter stenosis 65%–100%) and particularly those with late reperfusion therapy (time delay 180 min). In patients without a severe infarct-related stenosis,^99mTc-sestamibi was able to accurately distinguish viable from necrotic segments. Thus, rest^99mTc-sestamibi scintigraphy early after acute myocardial infarction may underestimate residual viability within the infarct region, particularly in patients with low flow state coronary anatomy, as a result of a severe infarct-related stenosis and/or late reperfusion therapy.This paper was presented in part at the European Nuclear Medicine Congress, Brussels, Belgium, August 1995     

A prenotification letter increased initial response,whereas sender did not affect response rates

ObjectiveTo find ways to improve response rates of medical and health surveys. We investigated whether a prenotification letter instead of a second reminder and varying senders of the questionnaires would affect response rates.Study Design and SettingWe present the results of two studies. In the first study, four groups were compared that either received a prenotification letter (group 1 and 2) or a second reminder letter (group 3 and 4); received the questionnaire from either a research institute (group 1 and 3) or a health insurance company (HIC; group 2 and 4). In the second study, we compared two groups that received the questionnaire sent by either a HIC or a hospital. Response rates, response speed, respondent characteristics, item nonresponse, and mean scores on quality aspects and global ratings were compared.ResultsResponse rates did not differ significantly between groups. Prenotification groups returned their questionnaires faster. No other significant differences were found for response speed, respondent characteristics, item nonresponse, or mean scores.ConclusionA prenotification letter does only increase initial response speed and does not increase total response rates. A prenotification letter should be considered when quick response is desirable. Varying senders had no effect on response rates.