Three-Dimensional Composition Analysis of SnAg Solder Bumps Using Ultraviolet Femtosecond Laser Ablation Ionization Mass Spectrometry.

The application of a novel UV fs Laser Ablation Ionization Mass Spectrometry approach for chemical depth profiling of low-melting point, high surface roughness SnAg solder bump features is presented. The obtained submicrometer resolved three-dimensional compositional data reveal unprecedented information on the distribution of individual elements inside the solder bump matrix. Moreover, the determination of matrix-matched relative sensitivity coefficients allows the first report on quantitative assessment of the SnAg alloy composition. These results significantly contribute to an in-depth understanding of the SnAg plating process. This experimental procedure may find application in future additive performance screening.

Tropisetron for treating established postoperative nausea and vomiting: a randomized, double-blind, placebo-controlled study.

UNLABELLED: Tropisetron can prevent postoperative nausea and vomiting (PONV) at doses smaller than those used to control chemotherapy-induced nausea and vomiting. In this placebo-controlled study, the efficacy and tolerability of three different doses of tropisetron were compared for the treatment of established PONV after surgical procedures in general anesthesia. Of 1513 patients who satisfied inclusion criteria, 314 experiencing PONV during the first 2 h after recovery from anesthesia were treated with one of three different doses of tropisetron (0.5, 2, or 5 mg) or placebo, administered i.v. as a single dose. Patients were then observed during 24 h for efficacy and tolerability. All three doses of tropisetron were significantly better than placebo in controlling emetic episodes and in reducing the need for rescue treatment. There were no significant differences among the three doses. However, in the subgroup of patients who had previous PONV, and in those randomized for nausea alone, the 2-mg and 5-mg doses controlled emetic episodes better than the 0.5-mg dose. All studied doses of tropisetron were well tolerated and did not affect vital signs. We conclude that a single i.v. administration of tropiestron significantly reduces the recurrence of emetic episodes in patients with established PONV after elective surgery with general anesthesia. Its optimal dose seems to be 2 mg. IMPLICATIONS: Three hundred-fourteen patients suffering from postoperative nausea and vomiting received different i.v. doses of a new antiemetic drug, tropisetron, to determine the lowest effective dose. We found that a single i.v. administration of tropisetron significantly reduced postoperative nausea and vomiting after elective surgery with general anesthesia.

Tropisetron for the prevention of postoperative nausea and vomiting in women undergoing gynecologic surgery.

The aim of this study was to evaluate the efficacy of tropisetron, a selective 5-hydroxytryptamine type 3 (5-HT3) receptor antagonist, versus placebo in the prevention of postoperative nausea and vomiting in patients undergoing general anesthesia for gynecologic surgery. Ten minutes before induction of general anesthesia, 80 patients received in a double-blind manner a single intravenous (IV) injection of either 5 mg tropisetron or a matching placebo. Anesthesia was induced with thiopental and maintained with nitrous oxide and enflurane in oxygen. In the first 24 h postoperatively 7 of 40 patients (17.5%) given tropisetron and 16 of 40 patients (40%) receiving placebo vomited (P < 0.05). The incidence of nausea was 30% (12/40) in the tropisetron group and 52% (21/40) in the placebo group (P < 0.05). A total effective antiemetic response showed 26 patients (65%) in the tropisetron group and 16 patients (40%) in the placebo group (P < 0.05). We conclude that tropisetron given IV prior to gynecologic procedures in general anesthesia significantly reduces postoperative nausea and vomiting when compared to placebo without causing any adverse effect.

Hypofibrinolysis in patients with a history of idiopathic deep vein thrombosis and/or pulmonary embolism.

An impaired fibrinolytic activity after a venous occlusion test is the most common abnormality associated with thomboembolic disease. To better characterize the causes of abnormal responses we have measured different fibrinolytic parameters, before and after 10 and 20 min of venous occlusion, in 77 patients with a history of idiopathic deep vein thrombosis and/or pulmonary embolism and in 38 healthy volunteers. The patients had a lower mean fibrinolytic response to venous occlusion than the controls and higher antigen levels of tissue-type plasminogen activator (t-PA:Ag) and plasminogen activator inhibitor type 1 (PAI-1:Ag). Before venous occlusion, PAI-1 levels were at a molar excess over those of t-PA in all patients and controls. After 20 min of venous occlusion, the release of t-PA from the vascular endothelium resulted in a molar excess of t-PA over PAI-1 in the majority of controls (72%) but only in a minority of patients (39%). To identify patients with fibrinolytic abnormalities, reference intervals (RI) for fibrinolytic activity, t-PA:Ag and PAI-1:Ag were established in healthy controls. None of the patients had low levels of t-PA:Ag, but 17 (22%) had elevated PAI-1:Ag levels before venous occlusion and 12 (16%) exhibited low fibrinolytic activity after 20 min of venous occlusion. Ten of these were among the 17 subjects with high PAI-1:Ag levels before venous occlusion. Thus, the measurement of PAI-1:Ag levels before venous occlusion (i.e. in samples taken without any stimulation) is a sensitive (83%) and specific (89%) assay for the detection of patients with an impaired fibrinolytic response to venous occlusion.

Plasma levels of plasminogen activator inhibitor type 1, beta-thromboglobulin, and fibrinopeptide A before, during, and after treatment of acute myocardial infarction with alteplase.

Plasma levels of plasminogen activator inhibitor type-1 (PAI-1), beta-thromboglobulin (beta TG), and fibrinopeptide A (FPA) were followed over 24 hours in 30 patients treated with alteplase for acute myocardial infarction. Samples were taken at baseline (T Oh), after 90 minutes (under alteplase, no heparin, T 1.5h), after 120 minutes (under alteplase and heparin, T 2h), 30 minutes after thrombolytic therapy (T 3.5h), as well as 12 hours (T 12h) and 24 hours (T 24h) after baseline. PAI-1 antigen levels (55 +/- 9 ng/mL at T Oh, mean +/- SEM) decreased to 35 +/- 5 (T 1.5h) and 40 +/- 6 (T 2h) ng/mL under alteplase, before increasing to 84 +/- 22 (T 3.5h), 130 +/- 30 (T 12h), and 64 +/- 7 (T 24h) ng/mL after therapy, P less than .001. A high baseline PAI-1 activity (18 +/- 3 ng/mL) decreased to 2.0 +/- 0.4 (T 1.5h) and 1.7 +/- 0.2 (T 2h) under alteplase and increased to 32 +/- 5 (T 12h) and 19 +/- 3 (T 24h) ng/mL after therapy (P less than .0001). beta TG levels (339 +/- 105 ng/mL at T Oh) decreased to 203 +/- 48 (T 2h), 154 +/- 51 (T 3.5h), 187 +/- 40 (T 12h), and 142 +/- 32 (T 24h) ng/mL under heparin (P less than .01). FPA levels (34 +/- 9 ng/mL at T Oh) increased to 85 +/- 15 ng/mL under alteplase alone (T 1.5h) and normalized under heparin (11 +/- 4, 6 +/- 2, 4 +/- 2, and 3 +/- 1 ng/mL at T 2h, T 3.5h, T 12h, and T 24h, respectively). A high level of FPA at T 3.5h correlated with reocclusion (33 +/- 12 ng/mL, n = 4 v 2.9 +/- 0.5 ng/mL, n = 21, P less than .005). We conclude that plasma levels of PAI-1 antigen as well as activity markedly increase after alteplase therapy of acute myocardial infarction. The high activity of PAI-1 and decreasing beta TG levels suggest that platelets do not contribute significantly to this phenomenon. The marked increase of FPA levels under recombinant tissue-type plasminogen activator alone and its normalization under heparin emphasize the important role of concomitant anticoagulation in controlling further intravasal fibrin generation under alteplase.

Antigen levels of plasminogen activator inhibitor type 1 in citrated plasma: determination of the contribution of platelets.

To estimate the extent of the release of plasminogen activator inhibitor type 1 (PAI-1) from platelets following their accidental activation in vitro during blood collection, we studied the antigen levels of PAI-1 and beta-thromboglobulin (beta TG) in plasma and sera from 38 healthy volunteers. For each volunteer, we calculated the ratio of platelet-derived PAI-1/platelet-derived beta TG from the difference in their respective concentrations in serum and plasma. The mean +/- SD (0.012 +/- 0.003) and median (0.012) ratios were identical before and after 10 or 20 min of venous occlusion. The platelet contribution of PAI-1 in plasma was estimated by multiplying the plasma concentration of beta TG (as a marker of platelet activation) with the above-mentioned individual ratio. Under our conditions of blood collection (1/10 vol of 0.1 M citrate, pH 4.5, as anticoagulant, and handling of blood at 4 degrees C and within 30 min), the platelet contribution to the PAI-1 concentration in plasma was on average 12% and always negligible in plasma with high levels of PAI-1.

Diurnal variation of the fibrinolytic system.

To elucidate which component(s) of the fibrinolytic system is (are) responsible for the diurnal variation of fibrinolytic activity we have studied several parameters of this system in 8 healthy male volunteers during a period of 24 h. Blood was collected at 8 a.m., 10 a.m., 12 a.m., 4 p.m., 8 p.m. and 8 a.m. next morning. The following tests were performed: euglobulin clot lysis time (ECLT), fibrinolytic activity of euglobulins on fibrin plates in the presence and absence of blocking antibodies to tissue-type plasminogen activator (t-PA) and/or urokinase (u-PA), overall plasminogen activator inhibitor (PAI) activity, antigen levels of t-PA, u-PA and PAI-1 and zymography of the euglobulin fraction after SDS-PAGE. From 8-10 a.m. to 4-8 p.m., total fibrinolytic activity increased by 113% (p less than 0.01) or 71% (p less than 0.01) when measured by ECLT or by fibrin plate assay, respectively. The immunoquenching experiments showed that this increase was entirely due to t-PA related activity whereas u-PA activity and t-PA/u-PA independent activity remained constant during the day. Average antigen levels of u-PA and t-PA in the afternoon were 6% and 25% lower than those measured in the morning. During this period, overall PAI activity and PAI-1 antigen decreased by 31% (p less than 0.01) and 52% (p less than 0.01) respectively. Electrophoretic-zymographic analysis of the euglobulins revealed that throughout the day the majority of t-PA was present in the form of the 110 kDa t-PA/PAI-1 complex. The intensity of this complex was lowest in the afternoon.(ABSTRACT TRUNCATED AT 250 WORDS)

Fibrinolytic and anticoagulant activity after a single subcutaneous administration of a low dose of heparin or a low molecular weight heparin-dihydroergotamine combination.

The anticoagulant and potential profibrinolytic effect of a combination of low molecular weight heparin with dihydroergotamine (LMWH-DHE) and of unfractionated heparin was studied in eight healthy volunteers. Each volunteer received a subcutaneous injection of either LMWH-DHE (1,500 U anti-Xa of LMWH + 0.5 mg DHE), unfractionated heparin (5,000 IU) or of placebo (saline) between 7 and 8 h in the morning on three different occasions. Anti-Xa activity, and fibrinolytic activity measured by the euglobulin clot lysis time (ECLT) and by the fibrin plate assay were determined before and at different times after administration of the three substances. Anti-Xa activity in plasma reached a maximum four hours after injection of both LMWH-DHE and unfractionated heparin. LMWH-DHE showed a better bioavailability when compared to unfractionated heparin; the anti-Xa activity peak was two and a half fold higher after LMWH-DHE despite injection of a three fold lower dose of anti-Xa units. The half-life of anti-Xa activity was approximately 4 hours for LMWH-DHE but only 90 min for unfractionated heparin. The fibrinolytic activity measured by ECLT as well as by fibrin plate assay, showed a significant increase during the day reaching a peak 8-12 h after injection regardless of the product administered (including the placebo). The profile of the diurnal fibrinolytic activity curve was identical for all three substances. The increase in fibrinolytic activity, observed after administration of LMWH-DHE or unfractionated heparin, was therefore not due to these drugs but reflected the circadian physiological fluctuation of fibrinolysis.