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Biomedical subjects

N Egberg

Publications and source records attributed to N Egberg.

At least 73 records · Page 4Linked to original sources
PubMed1990

Homozygous protein C deficiency in two siblings.

Homozygous protein C (PC) deficiency is reported in two siblings (girl and boy) who received their proper diagnoses at the ages of 7 4/12 and 1 3/12 years respectively. The girl had perinatal asphyxia without bleeding. At 1 year of age she developed purpura fulminans. Treatment with heparin and plasma was successful. At 7 4/12 years she developed tender, bluish nonnecrotic skin changes after an orthopedic operation. The PC level was 0.08 U/ml. The boy had had a large intraventricular hemorrhage neonatally and developed severe brain damage. At 1 3/12 years he manifested the same skin changes as his sister and was treated similarly. The PC level was 0.05 U/ml. Both children now receive warfarin continuously and are essentially free of symptoms. The cases represent homozygous phenotypes in a family with a recessive trait of PC deficiency without thrombotic disease. The cases also show that severe PC deficiency may be compatible with life beyond infancy without any specific therapy.

Blood Transfusion↗
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

Effect of acetyl salicylic acid on increased production of thromboxane after aortic graft surgery.

Contact between blood and foreign surfaces, e.g. vascular grafts, causes activation and release of platelets. One consequence of platelet activation is production of thromboxane A2 (TxA2). The physiological effects of TxA2, i.e. platelet aggregation and vaso-constriction are counteracted by another prostanoid, prostacyclin (PGI2). Acetylsalicylic acid (ASA) causes a longlasting inhibition of platelet TxA2 production and a more shortlasting inhibition of PGI2 production. The present study examines TxA2 and PGI2 synthesis in patients receiving synthetic arterial grafts, some of which were treated with ASA. The prostanoid synthesis was evaluated by measurement of their main urinary metabolites with gas chromatography-mass spectrometry. Platelet release was evaluated by measurements of beta-thromboglobulin (beta-TG) and the plasma coagulation by measurements of fibrinopeptide A (FPA). These compounds were also measured in urine in order to avoid artifacts caused by activation of platelets and plasma coagulation during blood sampling. Following replacement of the abdominal aorta with a synthetic vascular graft there was a marked increase in the synthesis of TxA2 and PGI2. Increased levels of beta-TG and FPA were also demonstrated. Administration of ASA on the first and second postoperative days significantly reduced the synthesis of TxA2 but caused no significant effects on the other parameters measured. It is concluded that ASA may be beneficial in the postoperative period since it counteracts TxA2 with vasoconstricting and platelet aggregating properties but leaves PGI2 with vasodilating and antiaggregating properties relatively uneffected.

Aged↗
PubMed1989

Altered platelet function during mental stress and adrenaline infusion in humans: evidence for an increased aggregability in vivo as measured by filtragometry.

1. The effects of mental stress induced by a colour word conflict test (CWT; n = 9) or 3 h infusions of placebo or adrenaline (0.4 nmol min-1 kg-1; n = 9) on platelet function in vivo were studied in 16 healthy male volunteers. 2. Platelet function was assessed by a filtragometry technique, which reflects aggregability in vivo, and by measurements of the plasma levels of beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4). 3. Adrenaline and CWT induced marked cardiovascular responses as expected. Venous plasma adrenaline increased from 0.1-0.2 nmol/l at rest to 4.87 +/- 0.42 nmol/l during adrenaline infusion and to 0.46 +/- 0.10 nmol/l during CWT. 4. Filtragometry measurements were reproducible within individuals with coefficients of variation of 7.9% during placebo infusion and 5.4% for resting measurements between days. 5. Platelet aggregability, as measured by filtragometry, was similarly increased during both adrenaline infusion (P less than 0.05) and CWT (P less than 0.01). 6. The coefficients of variation for beta-TG and PF4 levels were 17.3% for log beta-TG and 27.9% for log PF4 between days, but could not be calculated for within-day variability. Both beta-TG (P less than 0.05) and PF4 (P less than 0.01) levels decreased time-dependently during placebo infusion, indicating that long resting periods (hours) are needed to attain basal levels. Artefactual results could not be identified by evaluating beta TG/PF4 ratios. 7. beta-TG and PF4 levels did not decrease time-dependently during adrenaline infusion. There were no significant changes of beta-TG or PF4 during CWT.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
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

HIV-serology and lymphocyte subsets in relation to therapy and clinical development in haemophiliacs.

389 Swedish patients with haemophilia A, B or von Willebrand's disease were examined for HIV-1 antibodies. T-cell subsets were measured in 260 of them. HIV-1 antibodies were found in 98 of these patients. Of the 199 patients with severe or moderate haemophilia A, 44% were seropositive. They had seroconverted between 1979 and 1983. HIV-1-seropositive patients had significantly decreased numbers of CD4 cells and increased numbers of CD8 cells. The seronegative haemophilia A patients had significantly increased numbers of CD8 cells. The T-cell subsets were followed for a median of 40 months in 73 seropositive patients. All groups of patients, at different clinical stages, showed decreasing numbers of CD4 cells. The most pronounced decrease was seen in the patients who developed AIDS, followed by the group which developed HIV-related signs or symptoms. HIV antigen in serum and antibody pattern in Western blot and ELISA were followed in 89 patients. HIV-1 antigen was present and p24 antibodies were lacking in 11% and 13% of asymptomatic subjects, in 13% and 20% of patients with persistent generalized lymphadenopathy, in 33% and 38% of patients with other HIV-related signs or symptoms and in 5/6 of the AIDS patients, respectively. In conclusion, the decrease of CD4 cells and the presence of HIV antigen and/or absence of p24 antibodies were found to be prognostic markers for HIV disease.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Hemostatic disturbances associated with implantation of an artificial heart.

Coagulation and platelet parameters have been assessed following implantation of a Jarvik 7 artificial heart. Initially an ongoing intravascular coagulation could not be overcome with heparin and coumarin. The in vivo formation of thromboxane A2 (as monitored by measurement of the major urinary metabolite) was increased 3-4 fold. Administration of aspirin every second to third day reduced the thromboxane formation dramatically. In parallel to this, the intravascular coagulation subsided, the demand for heparin decreased considerably and the clinical condition of the patient improved. These events provide evidence for a direct link between thromboxane formation and the coagulation cascade. The thromboxane formation was insufficiently suppressed around the 110th postoperative day. Two weeks later the patient suffered a cerebral embolus, followed by a bleeding in the embolized area. This case illustrates the applicability of antiplatelet treatment when the need for efficient antithrombotic treatment is especially pronounced. Aspirin, however, is not the ideal drug for this purpose.

Blood Coagulation Tests↗
PubMed1987

A pilot study; desmopressin (DDAVP) in the treatment of deep venous thrombosis.

In a pilot study on 9 patients with acute deep venous thrombosis of the leg the fibrinolytic response and the possible thrombolytic effect of desmopressin (DDAVP), when given supplementary to standard heparin treatment, was examined. Six injections of 0.3-0.4 microgram DDAVP/kg b.w. at 12 hours intervals were given. No serious side effects were observed. The fibrinolytic variables that followed showed that plasma levels of t-PA increased significantly and most pronounced after the first injection. Rephlebography 4-7 days after hospitalization showed partial thrombolysis in 7 out of 9 patients. The phlebographic score according to Marder was reduced from 22.7 +/- 12.1 to 18.4 +/- 10.1 (p = 0.018), corresponding to a thrombus size reduction of 19%. No correlation between the level of the fibrinolytic variables measured and the degree of thrombolysis in the individual patients, could be demonstrated in this small number of patients.

Antigens↗
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↗
PubMed1987

Effects of vitamin E therapy on ethanol-induced changes in platelet aggregation, thromboxane formation, factor VIII levels and serum lipids.

A transient increase in platelet thromboxane formation has been observed in non-alcoholics during acute ethanol intoxication and in alcoholics shortly after ethanol withdrawal. Whether these effects are related to the generation of free radicals and lipid peroxidation was investigated by using vitamin E as a free radical scavenger and inhibitor of lipid peroxide formation. The results demonstrate that a high dose of vitamin E (1800 IU) taken daily by non-alcoholic men slightly (P less than 0.05) decreases aggregation-associated platelet thromboxane formation during ethanol oxidation. Likewise, vitamin E prevents the ethanol-induced increase (P less than 0.01) in factor VIII coagulant activity. These observations suggest that the enhancement of platelet thromboxane formation and factor VIII coagulant activity by acute ethanol ingestion may be related to stimulated lipid peroxidation. By contrast, similar effects of vitamin E were not found in alcoholics shortly after ethanol withdrawal suggesting other mechanisms for their platelet hyperreactivity.

Adult↗
PubMed1987

HIV infection in a defined population of Swedish haemophiliacs.

The results of a clinical follow-up of 124 Swedish patients with haemophilia A and B or severe form of von Willebrand's disease are reported, especially with regard to HIV infection and complications thereof. 44 of the patients were anti-HIV positive. In this group there was an increasing prevalence of lymphadenopathy (18 cases), diarrhoea and fungal infections. 10 patients had generalized persistent lymphadenopathy. Platelet counts were significantly lower and IgG, IgA and IgM levels significantly higher than in the anti-HIV negative group. Oligoclonal protein bands in the gammaglobulin region were found in 8 of the anti-HIV positive patients. The vast majority of these changes have appeared during the past year, and 1-5 years after seroconversion. Presently 22/44 (50%) anti-HIV positive haemophiliacs have at least one symptom related to this infection. Most of the clinical complications have been possible to treat or to mitigate so far.

AIDS-Related Complex↗
PubMed1986

Transmission of HIV infection to heterosexual partners but not to household contacts of seropositive haemophiliacs.

The prevalence of HIV antibodies in 44 heterosexual female partners and 56 nonsexual family household contacts of 61 HIV seropositive haemophiliacs (41 adults and 20 children or adolescents) was determined to evaluate the risk of transmission of HIV infection. HIV antibodies were determined by enzyme-linked immunosorbent assay and positive reactions were confirmed by Western blotting. HIV antibodies were demonstrated in 4/40 (10%) regular heterosexual partners of 40 seropositive patients with haemophilia A. Four temporary heterosexual partners of one additional seropositive haemophiliac were seronegative. 56 nonsexual household contacts including 30 parents, 13 siblings and 13 children of 29 seropositive haemophiliacs were all negative for HIV antibodies. Thus transmission of HIV occurred from seropositive haemophiliacs to their heterosexual partners but not to nonsexual household contacts.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Analyses of factor XII, prekallikrein and kallikrein inhibitory capacity in patients with laboratory signs of DIC.

We investigated 22 severely ill patients (21 surgical, 1 medical) at the intensive care unit. Analyses of platelet count, Normotest, antithrombin III, FDP and fibrinogen were used to divide the patients into three diagnostic groups: DIC (3 positive tests), suspected DIC (2 positive tests) and No DIC. Using these criteria 9, 8 and 5 patients were referred to these diagnostic groups, respectively. Factor XII and prekallikrein did not differ significantly between the three diagnostic groups. On the other hand the capacity of the patient plasma to inhibit kallikrein was significantly lower in the DIC group. The decrease of kallikrein inhibitory capacity was correlated to the decrease of antithrombin III and alpha 2-antiplasmin. Out of the 22 patients in the study 8 patients died, 5 of these were in the DIC group. Non-surviving patients showed lower values of the protease inhibitors than survivors. It is concluded that in this type of patients and with the laboratory methods used contact phase factors do not seem to be affected in DIC. Analyses of the kallikrein inhibitory capacity, antithrombin and alpha 2-antiplasmin on the other hand seem to be of interest to measure, though the decrease of these inhibitors could be due to consumption as well as to reduced protein synthesis. Further studies are needed to prove the prognostic value of assaying these protease inhibitors.

Critical Care↗
PubMed1984

Structure-function relationships of human factor VIII complex studied by thioredoxin dependent disulfide reduction.

A highly purified, multimeric factor VIII complex composed of VIII: vWF and some factor VIII: C contained about 100 disulfides per subunit of Mr 260,000. Limited reduction of disulfide bonds in this complex by NADPH, thioredoxin reductase and thioredoxin leads to partial disaggregation of the multimeric VIII:vWF with concomitant loss of its platelet agglutinating activity in the presence of ristocetin, and with dissociation of factor VIII:C from the complex. During this event, no Mr 260,000 subunit of VIII:vWF is discernible. However, prolonged reduction results in the appearance of different multimers, and of some Mr 260,000 subunits. An N-terminal amino acid sequence for VIII:vWF was deduced. Two half-cystine residues in this sequence were shown to be involved in the reaction with thioredoxin. It appears possible that the thioredoxin system or other redox systems may play a role in regulation of factor VIII activities and of hemostatic processes in vivo.

Amino Acid Sequence↗
PubMed1984

Blood coagulation and fibrinolytic factors and their inhibitors in critically ill patients.

In a search for new variables, for the diagnosis of disseminated intravascular coagulation (DIC) and for guidelines of therapy in such conditions, 22 severely ill patients were studied. The diagnosis of DIC was based on determinations of platelet counts, prothrombin complex (Normotest), antithrombin (AT), fibrinogen degradation products and fibrinogen. Nine patients were diagnosed as having DIC, eight patients were referred to a suspected DIC group and five to a group of no DIC. The laboratory findings were found to agree with the clinical status. In addition several new parameters were investigated: factor XII, prekallikrein, Simplastin A--another prothrombin complex factor method, factor X, plasminogen (PLG), antiplasmin (AP) and kallikrein inhibitors (KI). Platelet counts, prothrombin complex and antithrombin were mostly pathological in DIC-patients. Of the alternative tests prothrombin complex, fibrinopeptide A and the kallikrein inhibitor as well as the two tests for fibrinolysis (PLG and AP) were significantly altered in DIC-patients. The inhibitor capacity (AT, APV and KI) was lower in patients who died than in survivors and decreased still further in those of the non-survivors who had DIC. Thus the inhibitors can be used as predictors of outcome and hopefully for guiding therapy. To establish the diagnosis of DIC we suggest measurement of platelet count, prothrombin complex, plasminogen as well as of the inhibitors.

Adolescent↗