Biomedical subjects

Christel Weiss

Publications and source records attributed to Christel Weiss.

23 records · Page 2Linked to original sources

PubMed2003

Effects of lepirudin, argatroban and melagatran and additional influence of phenprocoumon on ecarin clotting time.

INTRODUCTION: Direct thrombin inhibitors (DTI) prolong the ecarin clotting time (ECT). Oral anticoagulants (OA) decrease prothrombin levels and thus interact with actions of DTIs on the ECT method during concomitant therapy. MATERIALS AND METHODS: Actions of lepirudin, argatroban and melagatran on ECT were investigated in normal plasma (NP) and in plasma of patients (n=23 each) on stable therapy with phenprocoumon (OACP). Individual line characteristics were tested statistically. RESULTS: Control ECT in OACP was prolonged compared to NP (50.1+/-0.9 vs. 45.7+/-0.8 s; p<0.001). Lepirudin prolonged the ECT linearly. Argatroban and melagatran delivered biphasic dose-response curves. OA showed additive effects on the ECT of lepirudin but not of argatroban and melagatran. Both in NP and OACP, the first and second slopes of melagatran were steeper compared to argatroban (primary analysis; p<0.001). When using the same drug, slopes in OACP were steeper than in NP (secondary analysis; p<0.001). At similar molar concentrations, the crossing points of both slopes were significantly higher with melagatran (323.1+/-11.0 s in NP and 333.2+/-8.2 s in OACP) than with argatroban (219.6+/-14.7 and 248.4+/-15.2 s) corresponding to ratios of 7.1+/-0.2 and 6.7+/-0.2 (melagatran) vs. 4.8+/-0.3 and 4.9+/-03 with argatroban (p<0.0001). DISCUSSION: The patterns of interactions between vitamin K antagonists and DTI effects are different for bivalent (increase of slope without affecting linearity) and monovalent inhibitors (slight increase or alteration of nonlinear slopes), but there are also differences between the two monovalent inhibitors on thrombin inhibition as determined by ECT.

Anticoagulants↗

PubMedDate not supplied

Observations of alanine aminotransferase and aspartate aminotransferase in THRIVE studies treated orally with ximelagatran.

Treatment of acute venous thromboembolism (VTE) and prophylaxis of recurrent events has been investigated in the THRIVE (THRombin Inhibitor in Venous Thrombe Embolism) Treatment and the THRIVE III trial using the oral direct thrombin inhibitor ximelagatran. Alanine aminotransferase (ALAT) increased in 9.6% and 6.4% of patients in the THRIVE Treatment and THRIVE III trials, respectively. The authors analysed the time course of the ALAT and in additionally of aspartate aminotransferase (ASAT) in blood from 52 and 23 patients participating in the THRIVE Treatment and the THRIVE III trials in Germany. Analysis of variance for repeated measures and t test were performed. In the THRIVE Treatment trial, ALAT was significantly higher at week 2 for enoxaparin/warfarin (p => .0039, t test) and at months 3 and 6 for ximelagatran (p = .0453, p = .0014, respectively). ASAT and ASAT/ALAT ratio values did not increase and not differ for both groups. In the THRIVE III trial, ALAT and ASAT did not increase and did not differ compared to the comparator placebo. 2 x 36 mg Ximelagatran, induced higher ALAT values at months 3 and 6 compared to 2 x 24 mg ximelagatran (p = .0105, p = .0063, respectively). ASAT did not differ between the two doses of ximelagatran. The ASAT/ALAT ratios were lower at week 2 for enoxaparin/warfarin (t-test, p = .0032) and at month 3 and 6 for 2 x 36 mg versus warfarin or 2 x 24 mg Ximelagatran (p between .0187 and .0002). The authors conclude that ALAT increases dose dependently during therapy with ximelagatran. The less frequent and lower increase of ASAT values compared to ALAT values indicates a nontoxic effect of ximelagatran on liver cells.

Administration, Oral↗

PubMedDate not supplied

Improvement of sensitivity and interrater reliability to detect acute stroke by dynamic perfusion computed tomography and computed tomography angiography.

OBJECTIVE: To assess the benefits of additional computed tomography perfusion (CTP) and computed tomography angiography (CTA) on the detection of early stroke, vessel occlusion, estimated infarct size, and interrater reliability. METHODS: Sixty-seven consecutive patients underwent nonenhanced computed tomography (CT) imaging, CTA, and CTP. The final diagnosis of stroke was made from follow-up neuroimaging. A first diagnosis was made on-site by the physician on duty. Three experienced neuroradiologists blinded to follow-up findings analyzed the data set off-line, evaluated CT for signs of acute stroke, and subsequently evaluated CTP and CTA for infarction-related perfusion deficits and vessel abnormalities. RESULTS: Computed tomography perfusion and CTA increased the time from CT start to diagnosis from 2 minutes to 10 minutes. Sensitivity to detect acute stroke increased significantly in all investigators from 0.46-0.58 to 0.79-0.90 compared with CT (<0.005). The interrater weighted kappa value increased from 0.35 to 0.64. Estimation of infarct size was not improved. CONCLUSION: Computed tomography perfusion and CTA provide an effective add-on to standard CT in acute stroke imaging by significantly increasing the sensitivity and reliability of infarct detection.

Acute Disease↗

PubMedDate not supplied

Biodegradation of absorbable sutures in body fluids and pH buffers.

OBJECTIVE: This study measures the influence of body fluids on the loss of tensile strength of absorbable sutures in vitro. METHODS: Nine synthetic absorbable sutures were incubated in different gastrointestinal fluids, as well as in blood and three buffers. Stretch tests were performed after days 0, 7, 14, and 21. RESULTS: Tensile strength varied from 18.5 to 32.8 N, and elasticity varied from 9.5 to 51% of the initial length. The influence of pH, blood, and gastric juice was negligible on all sutures except PDS II. Except for Monocryl, all sutures, especially Polysorb and Vicryl, lost tensile strength much faster in bile, jejunal and pancreatic juices than in the corresponding buffers. CONCLUSION: The biodegradation of sutures varies greatly in different body fluids independent of differences in pH.

Absorbable Implants↗

PubMedDate not supplied

The influence of early supplementation of parenteral nutrition on quality of life and body composition in patients with advanced cancer.

BACKGROUND: According to current evidence, most organizations, including the American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.), do not recommend the routine use of artificial nutrition for patients with cancer. Despite the recommendation for parenteral nutrition (PN), data for early PN supplementation (PNS) in patients with an advanced malignancy are extremely limited, especially in terms of the affects on nutrition outcomes, body composition, and quality of life (QOL), as well as effects on oncologic outcomes. The aim of the study was to evaluate the effect of PNS on body composition and the quality of life in patients with advanced malignancies. METHODS: One hundred fifty-two consecutive patients with advanced cancer were prospectively randomized to either use of oral enteral nutrition supplement (PN-) or use of oral enteral nutrition supplement plus supplemental PN (PN+). Body weight, body mass index (BMI), and caloric intake were assessed, and hemoglobin (g/dL) and serum albumin (g/L) were measured. Body composition was assessed by body impedance analysis (BIA), and QOL was evaluated by European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 questionnaire every 6 weeks. RESULTS: No significant differences were evident at baseline between the 2 groups for age, gender, medical diagnosis, weight, BMI, or QOL. A statistically significant difference in mean BMI was observed by week 48 for the PN+ group (PN+ = 21.9, PN-= 20.5, p = .0149), by week 6 in mean body cell mass (PN+ = 55%, PN-= 50,1%, p < .001), mean albumin (PN+ = 40.2 g/L, PN-= 36.2 g/L, p = .015), mean QOL (PN+ = 55.7, PN-= 50.9, p = .035). The cumulative survival rate was significantly greater in the PN+ group (p < .0001). CONCLUSIONS: According to the positive effect of supplemental PN on survival, body composition, and QOL, additional controlled studies must be conducted to confirm these findings.

Body Composition↗