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Biomedical subjects

J J Borm

Publications and source records attributed to J J Borm.

26 records · Page 2Linked to original sources
PubMed1989

Enhanced thrombin generation in normal and hypertensive pregnancy.

We investigated the plasma levels of thrombin-antithrombin III complexes in women with uncomplicated pregnancy, patients with preeclampsia, gestational hypertension, and nonpregnant control subjects. In addition, we measured the coagulation inhibitors antithrombin III, protein C, and protein S. In normal pregnancy we observed a progressive increase in plasma thrombin-antithrombin III levels, and a decrease in protein S levels. In preeclampsia we observed increased thrombin-antithrombin III levels, reduced antithrombin III and protein C levels, and no further reduction of protein S compared with normal pregnancy. These new methods provide solid evidence for a prethrombotic state in normal pregnancy, especially in preeclampsia.

Adult↗
PubMed1988

Placental-type plasminogen activator inhibitor in preeclampsia.

The present cross-sectional study in patients with preeclampsia and gestational hypertension and in gestational age-matched controls was undertaken to investigate further the fibrinolytic system in these conditions. In preeclampsia we observed increased levels of total plasminogen activator inhibitor (p less than 0.001) but low levels of placental-type plasminogen activator inhibitor (p less than 0.05) compared with controls. The levels of placental-type plasminogen activator inhibitor were even more reduced (p less than 0.002) in pregnancies with a poor fetal outcome. It is concluded that placental-type plasminogen activator inhibitor does not contribute to the increased levels of total plasminogen activator inhibitor activity in preeclampsia. Placental-type plasminogen activator inhibitor levels correlated significantly with birth weight and placenta weight and may therefore reflect placental function.

Adult↗
PubMed1988

Laboratory and clinical evaluation of an assay of thrombin-antithrombin III complexes in plasma.

We evaluated a recently developed commercial assay for quantifying thrombin-antithrombin III (TAT) complexes in human plasma. The assay is precise (within-assay CV less than 10%, between-assay CV less than 13%), and sensitive (detection limit 0.7 micrograms of TAT per liter of plasma). Measurements for healthy volunteers yielded a normal reference (95 percentile) interval of 0.8 to 5.0 micrograms/L (n = 50, mean 2.1 micrograms/L, range 1.1 to 7.5 micrograms/L). TAT concentrations were increased in 25 of the 41 patients who fulfilled the clinical criteria of disseminated intravascular coagulation (DIC, overall mean 15.8 micrograms/L) and in 30 of the 35 patients with deep-vein thrombosis of the leg (overall mean 9.4 micrograms/L). We assessed the accuracy of the TAT assay by comparison with established criteria for the laboratory diagnosis of DIC involving various cutoff values for antithrombin III, factor V, fibrinogen, platelet count, fibrin/fibrinogen degradation products, and activated partial thromboplastin time. The low specificity of the TAT assay with regard to some of these criteria indicates that the latter are probably insensitive.

Antithrombin III↗
PubMed1987

Analytical and clinical evaluation of commercial protein C assays.

Protein C deficiency is an important risk factor for thrombosis. Recently several commercial assays for this protein have become available. We evaluated two antigen and three activity assays in 50 healthy volunteers, 52 patients with deep venous thrombosis (DVT) proven by positive impedance plethysmography (IPG) and flebography, and 48 control patients referred to us for objective diagnosis of DVT but with repeatedly negative IPG. All subjects were less than 50 yr of age. Based upon assay performance, correlation of the assays, influence of heparin, and practical ease, an ELISA antigen assay and a chromogenic activity assay are recommended. The prevalence of protein C deficiency cannot be accurately determined from this study, because 3 DVT negative and 13 DVT positive patients were receiving coumarin therapy. However, based upon protein C:factor II antigen ratios, at least 7 of the DVT positive patients are likely to be protein C-deficient. Protein C determination should, therefore, be considered in all DVT patients less than 50 yr of age.

Chromogenic Compounds↗
PubMed1986

Heparin versus low molecular weight heparin K 2165 in chronic hemodialysis patients: a randomized cross-over study.

Ten patients on chronic intermittent hemodialysis treatment received either unfractionated heparin or low molecular weight (LMW) heparin K 2165 in a single-blinded randomized cross-over study to assess: effects on hemostasis and ex vivo platelet functions, and effectiveness, i.e. prevention of fibrin formation in the extracorporeal circuit. The 20 dialysis treatments were without untoward side effects, for both drugs used. The variation in the plasma anti-Xa activities was significantly less during K 2165 treatment than during heparinization. No differences between the drugs were observed regarding the Ivy bleeding time, platelet count and platelet aggregation (spontaneous, and induced by ADP and collagen). Plasma platelet factor 4 levels did not increase under K 2165 to such an extent as under heparin. Both drugs did not influence the plasma levels of beta-thromboglobulin, thromboxane B2 and platelet serotonin content. K 2165 did not affect platelet adhesion to collagen, in contrast to heparin which substantially inhibited platelet adhesion. Under both treatments, 4 minor clots were observed in 4 artificial kidneys, despite plasma anti-Xa levels in between 0.19 and 0.46 U/ml. K 2165 may therefore be considered as effective an anticoagulant as heparin, with less effects on ex vivo platelet functions.

Adult↗
PubMed1983

Antithrombin III levels in normotensive and hypertensive pregnancy.

Antithrombin III (AT III) is the main physiological inhibitor of blood coagulation. In a prospective study, plasma AT III was determined in 653 women during pregnancy, using an automated amidolytic technique. A control value 8 weeks after delivery was obtained in 192 of the women. In women with pregnancy-induced or aggravated hypertension a significant decrease in AT III levels was observed compared with normotensive controls of the same period of gestation and compared with the patients' own control values 6-8 weeks after delivery. No AT III depression occurred in patients with chronic hypertension during pregnancy. Patients with pregnancy hypertension and proteinuria had lower AT III levels than those without proteinuria, whose AT III levels were also depressed. Lowest AT III levels were seen in 2 eclamptic patients and in patients with severe preeclampsia, whose pregnancies were terminated for fetal distress while the infants were still preterm. Monitoring At III levels is of value in preeclampsia.

Adult↗
PubMedDate not supplied

No gender bias in referral for coronary angiography after myocardial perfusion scintigraphy with technetium-99m tetrofosmin.

BACKGROUND: Several studies have shown that the application of diagnostic and invasive procedures varies between men and women. The purpose of this study was to assess if referral for coronary angiography after technetium-99m tetrofosmin myocardial perfusion scintigraphy in 616 patients with undiagnosed chest pain might demonstrate gender bias. METHODS AND RESULTS: The primary end point for this study was coronary angiography within 90 days of myocardial perfusion scintigraphy. Women had more normal perfusion images than men (207 [70.9%] vs 160 [50.5%], P < .05). Of 242 patients with abnormal images (157 men, 85 women), 28 men (17.7%) and 17 women (20.0%) were referred for further invasive testing (P = not significant). Referral for coronary angiography increased relative to the number of defects. Univariate analysis showed that reversible and persistent defects were the most predictive variables for referral to coronary angiography (odds ratio [OR] 5.45, 95% confidence interval [CI] 3.10-9.58, P < .001, and OR 2.67, 95% CI 1.52-4.67, P = .001, respectively). More importantly, multivariate analysis showed that reversible perfusion defects (OR 4.77, 95% CI 2.48-9.17, P < .001) and persistent perfusion defects (OR 2.14, 95% CI 1.11-4.14, P = .02) were predictive of subsequent coronary angiography. No significant association between gender and subsequent coronary angiography was found both in univariate and multivariate logistic regression analysis (OR 0.64, 95% CI 0.37-1.12, P = .12, and OR 0.70, 95% CI 0.36-1.36, P = .28, respectively). CONCLUSIONS: Our study reveals that after correction for the presence and the severity of myocardial perfusion abnormalities, men and women were referred to coronary angiography at a similar rate. Thus, based on the results of technetium-99m tetrofosmin myocardial perfusion imaging, no substantial evidence for a gender-related bias could be found in the referral for further invasive testing.

Analysis of Variance↗