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Biomedical subjects

H Johnsson

Publications and source records attributed to H Johnsson.

At least 55 records · Page 3Linked to original sources
PubMed1991

Heparin, DDAVP and the bleeding time.

The effect on the bleeding time of heparin, followed by an infusion with desmopressin (DDAVP) 0.3 micrograms/kg or placebo in a randomized, double-blind set-up, was investigated in 20 patients treated for acute venous thromboembolism. The bleeding time was on the average prolonged by 90% (95% confidence interval 46%-134%) after at least 1 day of treatment with heparin. At that point DDAVP shortened the bleeding time by 23% with a confidence interval of -35% to -11% whereas the effect of placebo was -2% with a confidence interval of -23% to +20%. There was also a shortening of the APTT after DDAVP but not after placebo. It is concluded that DDAVP induces a partial reversal of the effect of heparin on the bleeding time, and that DDAVP should be tried in case of hemorrhagic problems.

Adult↗
PubMed1991

The role of a commercial latex agglutination test in the diagnosis of group B streptococcal infection in neonates.

An open prospective multicenter study was conducted in order to evaluate the Wellcogen Strep B latex agglutination test in the diagnosis of group B streptococcal (GBS) infections in neonates. Twenty-three (5.9%) of 391 urine specimens and 5 (1.2%) of 404 sera assayed were positive. The results of the urine tests corresponded to a sensitivity of 0.78 for bacteremic, 0.50 for non-bacteremic and 0.53 for all GBS associated (bacteremic, non-bacteremic and suspected) infections. After 20-25-fold concentration of urine specimens the sensitivity increased to 1.0 for bacteremic, 0.67 for non-bacteremic and 0.78 for all GBS associated infections. The specificity of the test was high (0.93 for concentrated urines), and the predictive value of a positive test (Pvpos) was 0.68. A positive latex test was highly predictive of positive surface cultures for GBS (Pv pos = 0.83 after concentration).

C-Reactive Protein↗
PubMed1990

Increased thromboxane formation in patients with antiphospholipid syndrome.

Thirty-one patients with IgG antibodies to cardiolipin (ACLA) were studied to determine their in vivo formation of the platelet aggregating and vasoconstricting substance thromboxane A2 (TxA2) and the platelet inhibiting and vasodilating substance prostacyclin (PGI2). This was done by measurements in urine of their enzymatically formed metabolites 2,3-dinor-TxB2 and 2,3-dinor-6-keto-PGF1 alpha, respectively, using gas chromatography-mass spectrometry. It is demonstrated that patients with IgG ACLA have a highly significant increase in the biosynthesis of TxA2 compared with age-matched healthy controls (807 +/- 163 [SEM] vs. 230 +/- 15 pg mg-1 creatinine, P = 0.0000005). A significant increment of the formation of PGI2 was also found (189 +/- 23 (SEM) vs. 125 +/- 11 pg mg-1 creatinine, P = 0.03), although this was much less pronounced than that for TxA2. We conclude that the highly increased formation of TxA2, reflecting platelet activation, in patients with IgG ACLA is of pathophysiologic relevance for their tendency to arterial and venous thrombosis and hence that they should be considered for prophylactic treatment with inhibitors of TxA2 formation, like aspirin.

Adult↗
PubMed1990

Thermography and plethysmography, a non-invasive alternative to venography in the diagnosis of deep vein thrombosis.

One plethysmographic and two thermographic methods were evaluated against venography in 102 patients with suspected deep vein thrombosis (DVT). Seventy-one patients had venographically verified DVT, which in 21 cases was restricted to the calf. Plethysmography (PG) gave a sensitivity and specificity of 63% and 94%, respectively. The former was influenced by a limited sensitivity of 14% in the sub-group with distal DVT. The sensitivity and specificity of temperature profiles (TP) were 87% and 39%, respectively, while the corresponding values for thermo-camera (TC) were 83% and 55%, respectively. Using a combined diagnostic approach of PG and TP, additional evaluation of posterior and lateral profiles and pattern recognition, 96% sensitivity and 81% specificity were reached. The combination of PG and TP will be an essential diagnostic complement when venography is not possible or inconclusive, as well as having a role in diagnostic screening in a large number of patients.

Adult↗
PubMed1989

Surgery in patients with von Willebrand's disease.

The risk of bleeding complications in the surgical treatment of patients with von Willebrand's disease has been evaluated. Sixty-four major surgical procedures were performed in 51 patients with various forms of von Willebrand's disease. In 18 cases, the bleeding disorder was unknown at the time of surgery, resulting in bleeding complications in 12 cases (67 per cent). Forty-five operations were carried out in patients in whom the diagnosis of von Willebrand's disease was known at the time of surgery. In these patients, the following haemostatic preparations were given: factor concentrate, fresh plasma, tranexamic acid and desmopressin. Haemostatic complications occurred in three of these operations (6.7 per cent); all were managed easily. No mortality was observed. It is concluded that patients with von Willebrand's disease do not carry an increased operative risk if appropriate precautions are taken.

Adolescent↗
PubMed1989

Oral surgery in patients with hereditary bleeding disorders. A survey of treatment in the Stockholm area (1974-1985).

The results on the oral surgical management of patients with coagulation disorders at the Karolinska Hospital, Stockholm, during the period 1974-1985 have been compiled and compared with those obtained during the period 1965-1973. The present study included 380 tooth extractions performed in 250 treatment sessions in 107 patients. The incidence of postoperative bleeding and duration of hospitalization were reduced during the period of investigation.

Blood Coagulation Disorders↗
PubMed1989

Acute effects with reference to thrombogenicity and liver toxicity after injection of different coagulation factor concentrates.

In order to assess thrombogenicity and liver toxicity of different coagulation factor concentrates, antithrombin III, soluble fibrin, alanine aminotransferase (ALAT) and gamma-glutamyl transpeptidase (GT) were measured in samples taken before, 30 min and 24 h after the infusion. Seventy-six studies were performed in 55 patients with haemophilia A (37), B (11) or von Willebrand's disease, type III (7). A sharp rise of soluble fibrin was observed in 2 patients with haemophilia B, indicating that modern factor IX concentrates may still be thrombogenic. A slight increase was also seen after infusion of factor VIII-von Willebrand factor concentrates of low purity. Antithrombin III, ALAT and GT did not change significantly after any of the factor concentrates. The alterations in those parameters did not correlate with the impairment of liver function.

Adult↗
PubMed1989

Induced antibodies to von Willebrand factor.

Plasma from 15 patients with haemophilia A and 4 patients with von Willebrand's disease (VWD) has been investigated for the presence of antibodies to von Willebrand factor (VWF) using ELISA and immunoblotting systems. All plasma samples were also analyzed for anticoagulant activity against factor VIII coagulant activity (FVIII:C) and ristocetin co-factor activity of VWF (RCof). The patients were on regular prophylaxis or treated 'on demand' with different commercial FVIII-VWF complex concentrates. Neutralizing activity against FVIII:C was only found in haemophiliacs (in 3 out of 15), whereas anti-RC of was only found in VWD patients (in 2 out of 4). In ELISA, antibodies to VWF were detected in 3 of the VWD patients. However, using the immunoblotting system, antibodies to the multimeric structure of VWF were found not only in VWD patients (in 3 out of 4); remarkably 9 out of 15 haemophiliacs also reacted with VWF, including some that did not show FVIII:C inhibitors. The pattern of VWF multimers obtained with the antibodies showed differences among the patients. These findings are discussed together with the mechanisms by which such antibodies could have developed in haemophilia A patients who are not deficient in this particular protein (VWF).

Adult↗
PubMed1989

Determination of vitamin D3 in margarines, oils and other supplemented food products using HPLC.

The vitamin D3 content of high fat foods, such as margarines and oils, was determined by liquid chromatography. The method involved sample saponification and an extraction process, in which the purification of the non-saponifiable matter was the critical step. A semi-preparative straight-phase clean up procedure was used to produce an adequately purified sample solution prior to the final analytical quantification step. Vitamin D2 was used as internal standard when estimating the vitamin D3 content. The overall recoveries depended on the fat content of the food sample and varied from 40% for margarines to 80% for low-fat products at a concentration of about 10 micrograms/100 g. The minimum detectable amount was 0.36 ng vitamin D3. The mean relative recovery of vitamin D3 in relation to vitamin D2 was calculated to be 0.97.

Animals↗
PubMed1988

In vivo effects of a low molecular weight heparin fragment on platelet aggregation and platelet dependent hemostasis in dogs.

Plasma defibrinogenated dogs were used to study the influence of conventional heparin and a low molecular weight heparin fragment (Fragmin, mean MW 5,000 d) on platelet dependent hemostasis. The heparins were given intravenously in gravimetrically equal doses. The bleeding from standardized skin flap wounds and platelet aggregation (ADP and thrombin) was studied. In comparison, higher doses of the fragment than of heparin were required to increase the bleeding. ADP-induced aggregation in defibrinogenated platelet rich plasma (after addition of normal dog plasma) was potentiated by both heparins. After injection of heparin or the fragment, ADP induced platelet aggregation without prior addition of normal plasma to the test-tube. In conclusion the heparin fragment affected bleeding to a less extent than conventional heparin. One explanation might be a weaker inhibition of thrombin-induced platelet aggregation.

Animals↗
PubMed1988

Immediate effects of heparin and LMW heparin on some platelet and endothelial derived factors.

Heparin and a low molecular heparin fragment, injected intravenously in volunteers, increased the plasma concentrations of platelet factor 4, but did not induce platelet activation as judged from excretion of 2,3-dinor-TxB2 (a major thromboxane A2 metabolite) and beta-thromboglobulin (btg) in urine and from btg levels in plasma. Heparin prolonged, within the normal range, the bleeding time in all six subjects. Platelet aggregation in platelet rich plasma was potentiated by both heparins, but platelet number, mean platelet volume and platelet distribution width were not affected. No evidence for endothelial release of prostacyclin was obtained as judged from urinary excretion of 2,3-dinor-6-keto-PGF1 alpha (a major prostacyclin metabolite), and plasma concentrations of tissue plasminogen activator, its inhibitor (PAI-1) and the von Willebrand-factor were unchanged.

Adult↗
PubMed1988

One-year sequential follow-up of venous emptying rate and leg temperature profiles after acute deep vein thrombosis.

In order to study the natural course of venous flow and temperature reaction in the legs after symptomatic first episode of deep vein thrombosis (DVT), 65 patients (57 with proximal DVT) without further thromboembolic complications during the observation period were followed for 1 year by repeated plethysmography (PG) and thermography (TG). Regarding the non-invasive parameters substantial individual variations was observed during the observation period. After 1 year pathologic PG and TG were still demonstrated in 39% (I mu (95%) = /0.43 +/- 0.05/) and 65% (I mu (95%) = /1.18 +/- 0.11/), respectively, of the patients after proximal DVT. Only a minority of the patients were normalized permanently in both PG and TG during the first year. The high frequency of remaining venous obstruction and especially, persistent thermoactivity is notable and may be of clinical importance.

Adult↗
PubMed1987

Thromboxane and prostacyclin formation in patients with deep vein thrombosis.

The urinary excretion of 2,3-dinor-TxB2 and 2,3-dinor-6-keto-PGF1 alpha (the major urinary metabolites of thromboxane B2 and prostacyclin) was measured in ten patients with confirmed deep vein thrombosis, using specific methods based on gas chromatography - mass spectrometry with deuterium-labelled internal standards. Measurements of these major urinary metabolites makes it possible to monitor the in vivo formation of thromboxane A2 and prostacyclin. The results demonstrate an abnormally high and very variable excretion of 2,3-dinor-TxB2 and 2,3-dinor-6-keto-PGF1 alpha in patients with deep vein thrombosis. This indicate that both thromboxane A2 and prostacyclin are involved in the course of events associated with this disease.

6-Ketoprostaglandin F1 alpha↗
PubMed1987

DDAVP-induced correction of prolonged bleeding time in patients with congenital platelet function defects.

In 37 patients with prolonged bleeding time, where thrombocytopenia, von Willebrand's disease or deficiency of other coagulation factors could be excluded, we have evaluated the effect of a DDAVP-infusion (0.2 ug/kg) together with tranexamic acid (10 mg/kg). Patients with acquired impairment of primary hemostasis were not included, except two cases where this could have been a contributing factor. The bleeding time was completely normalized in 27 cases and partially corrected in three more patients. The predominant feature among those, who did not respond, was a pattern compatible with thrombasthenia or cyclooxygenase deficiency, as assessed by platelet aggregation studies. Among the patients, in whom DDAVP was effective, this drug was thereafter successfully used as an alternative to blood products in 8 cases during and after surgery or delivery.

Adolescent↗