摘要:

Three LMW heparins (LMWH), one unfractionated heparin (UH), and international standards of LMWH and UH were compared in three chromogenic substrate (CS) assays and the ‘Heptest’ clotting assay. With a two-stage CS assay, linear standard curves were obtained in the 0.1–1.0 U/ml range, nearly coinciding for all preparations. With the one-stage CS assays, standard curves were curvilinear and similar for UH and the LMWH groups. In the Heptest assay, standard curves were linear for UH but not for LMWH. Mean recovery of LMWH, added to patients’ plasma samples was 70–98% for the four assays. Variation between individual recoveries was much greater with Heptest (coefficient of variation (CV) 35–44%) than with one-stage CS assays (CV 14–21 %) or two-stage CS assays (CV 7–8 %). For monitoring LMW heparin therapy, CS assays seem preferable to Heptest. The two-stage CS assay had superior accuracy, but the one-stage CS assays were ea

ISSN:1424-8832    

DOI:10.1159/000216127

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

In an animal model, the effect of a high dose of conventional heparin (2 IU/g s.c. twice a day) and a low-molecular-weight heparin (LMWH; Fragmin, 1 anti-Xa U/g once a day) was compared with that of placebo on the mineral bone mass in the femur of rats. After 33 days of treatment no differences were found in the weight of the femur. But heparin-treated rats exhibited a lower density (1,249 ± 0.046 g/ml as compared with that in control rats (p = 0.00007) and also in LMWH-treated rats (p = 0.001). Similarly, statistically significant differences have been found in ash contents. They were higher in control rats than in heparin-treated rats (p = 0.0002), and also slightly higher than in LMWH-treated rats (p = 0.01). Our findings suggest that LMWH may have a lower osteopenic effect than that of conventional heparin

ISSN:1424-8832    

DOI:10.1159/000216128

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

Several assay systems have been proposed for detection of the lupus anticoagulant (LA). We compared several screening and confirmatory tests used for the detection of LA in 108 patients. LA was detected in 52 plasmas. The activated partial thromboplastin time (APTT) and the dilute Russell viper venom time (DRVVT) were the most sensitive screening tests as compared to the kaolin clotting time (p < 0.001). The platelet neutralization procedure in both the APTT and DRVVT systems was superior to APTT performed with high phospholipid concentration (p < 0.01) and tissue thromboplastin inhibition (p < 0.001) as confirmatory tests. There was an association between the presence of LA and antiphospholipid antibodies detected by the enzyme-linked immunosorbent assay (p < 0.001). In summary, our results show that APTT may be a sensitive test for the detection of LA when an appropriate reagent is employed, and that freeze-thawed platelets are more effective than phospholipids to neutralize LA activity.

ISSN:1424-8832    

DOI:10.1159/000216129

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

Disulfiram was studied for platelet and fibrinolytic activity in 12 healthy volunteers of both sexes (age 23–75 years). Placebo was given for 7 days, followed by disulfiram, 800 mg for 2 days and 400 mg for an additional 12 days. Finally, there was another placebo period of 14 days. With the exception of an initial platelet activation on day 2, no significant effects were found on the platelet variables studied: platelet aggregation with collagen, ADP and adrenaline, β-thromboglobulin and platelet factor 4. Treatment for 14 days with disulfiram resulted in a decreased euglobulin clot lysis time: from 421 ± 82 to 246 ± 41 min (p < 0.01). After an initial increase, plasminogen activator inhibitor activity was slightly decreased on disulfiram, from 8.4 ± 1.6 on placebo to 6.0 ± 1.2 U/ml (p < 0.05) after 14 days of treatment. Plasminogen, fibrinogen and α2-antiplasmin were unchanged. It is concluded that disulfiram can increase fibrinolytic activity in healthy s

ISSN:1424-8832    

DOI:10.1159/000216130

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

To elucidate the mechanism of enhanced ristocetin-induced platelet aggregation (RIPA) in steroid-responsive nephrotic syndrome (SRNS), plasma levels of von Willebrand factor antigen (vWF:Ag) and ristocetin cofactor (RCof) were examined in 6 patients and the amount of ristocetin-induced vWF binding to platelets was determined. At the initial or relapse stage, the plasma vWF:Ag level was 415 ± 137% and the RCof level was 364 ± 1.17%. The ratio of RCof/vWF:Ag was 0.90 ± 0.15 and no abnormalities of vWF:Ag multimers were observed, indicating that neither functional nor structural abnormalities were present in patient’s plasma. The amount of ristocetin-induced normal vWF binding to nephrotic washed platelets, when ristocetin was used at concentrations of 0.5, 0.75, and 1.0 mg/ml, was 152–163% above the binding to normal platelets. In addition, nephrotic washed platelets resuspended in either normal or nephrotic plasma aggregated at a low concentration of ristocetin (0.75 mg/ml) which did not induce aggregation of normal platelets. In accordance with these observations, the decrease of Alcian blue 8GX binding to platelets, reflecting diminished surface negative charge, was also observed. These results appear to indicate that the plasma vWF level and the altered surface-negative charge in platelets both contribute to heightened vWF binding to GPIb, thus lowering the ristocetin concentration required for RIPA i

ISSN:1424-8832    

DOI:10.1159/000216131

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

The ability of human peripheral blood monocytes to secrete plasma serine protease inhibitors was studied. Monocytes from blood obtained from healthy young adult volunteers were cultured for up to 36 h with and without lipopolysaccharide from Escherichia coli. The concentrations of plasma serine protease inhibitors in monocyte culture supernatants were measured by using rocket immunoelectrophoresis. The study showed that human monocytes stimulated with lipopolysaccharide in vitro release antithrombin III, C1 esterase inhibitor, α2-antiplasmin, and α2-macroglobuli

ISSN:1424-8832    

DOI:10.1159/000216132

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

The effect of unilateral or bilateral orchidectomy on tissue plasminogen activator activity (PAA), plasminogen activator inhibition (PAI) and plasmin inhibition (PI) was studied in the rat. Orchidectomy was performed in young or adult rats. Unilateral orchidectomy affected only PI in the lungs and brain, 1, 2 and 3 months after orchidectomy was performed in adult rats. Bilateral orchidectomy performed in young or adult rats affected one or more of the parameters studied in one or more of the key organs (brain, lungs, kidneys, heart, aorta), in most cases only 2 and 3 months after orchidectomy. Therefore, the effect of orchidectomy on tissue PAA, PAI or PI was variable and dependent on the extent of the orchidectomy (unilateral or bilateral), the age of the animal at orchidectomy, the time after orchidectomy, and the organ.

ISSN:1424-8832    

DOI:10.1159/000216133

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

We investigated 148 diabetic patients with regard to their relationship between fibrinolysis (D-dimer and plasminogen activator inhibitor; PAI) and glycometabolic control (HbA1c, HbA1 and fructosamine). The percentage of moderately controlled patients as indicated by HbA1c, HbA1 and fructosamine is relatively high (29.7, 41.7 and 30.4%, respectively). Simultaneously, the D-dimer and PAI levels turned out to be enhanced in 30.8 and 22.4% of the patients. There was a positive nonsignificant correlation between D-dimer and HbA1c, a highly significant negative correlation between D-dimer and HbA1 and a nonsignificant negative correlation between D-dimer and fructosamine. According to the upper limits of the distinct reference ranges for HbA1c, HbA1 and fructosamine, we splitted up the .D-dimer results and calculated the mean D-dimer values belonging to each category. Comparing the D-dimer means for each parameter, we separately obtained significant differences of the D-dimer means between the lower and higher HbA1 and fructosamine groups, whereas in the case of HbA1c the mean D-dimer values of the categories under and over 9% showed no significant difference. For PAI, we found only weak nonsignificant positive correlations to D-dimer and fructosamine and weak but highly significant correlations to HbA1c. These results are indicative for an increase of PAI with diminished glycometabolic control as measured with the HbA1c and fructosamine level. Both D-dimer and PAI showed positive, highly significant correlations to the age of the diabetic patients, whereas HbA1c and fructosamine were age independent. The results described in this report demonstrate that the fibrin degradation to D-dimer fragments by the specific fibrinolytic enzyme plasmin is dependent on the glycometabolic control state as measured with HbA1 and fructosamine and thus on the nonenzymatic glycosylation, which reduces the susceptibility of fibrin to degradation by plasmin.

ISSN:1424-8832    

DOI:10.1159/000216134

出版商:S. Karger AG    

年代:1990

数据来源: Karger

ISSN:1424-8832    

DOI:10.1159/000216135

出版商:S. Karger AG    

年代:1990

数据来源: Karger