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Biomedical subjects

U Hedner

Publications and source records attributed to U Hedner.

At least 37 records · Page 2Linked to original sources

Familial antithrombin III deficiency as pathogenesis of deep venous thrombosis.

A family including 18 members with decreased antithrombin III (AT III), measured with both a biological and an immunochemical method, is described. The pattern found on crossed immunoelectrophoresis, using heparin in the agarose in the first run, was normal, though the peaks were low. This suggests decreased synthesis of a normal protein in the affected members. AT III deficiency occurred in both the paternal and the maternal branch, of the above 18 persons had had at least one thromboembolic episode. Some of the episodes had been precipitated by the presence or occurrence of some predisposing event or circumstance. This suggests the possible occurrence of a gene making some of the maternal family members more susceptible to certain trigger factors, such as surgery, infection, pregnancy, and the puerperium. The mode of inheritance filled all the criteria for autosomal dominant transmission. Prophylactic treatment, preferably oral anticoagulants and/or dextran, is recommended for all persons with a low AT III concentration in any situation known to increase the predisposition to thrombosis. The effect of heparin in these patients is impaired since the heparin co-factor, which is identical with AT III, is lowered.

Adolescent

A family with thromboembolic disease associated with deficient fibrinolytic activity in vessel wall.

Defective fibrinolytic activity is often a contributory factor in deep venous thrombosis. A family with a high incidence of venous thrombosis in association with such a defect is presented. Of 13 family members who had had thrombosis, 12 showed a defective capacity to release fibrinolytic activity from vessel wall after venous occlusion and/or infusion of DDAVP, a vasopressin derivative. The fibrinolytic activator activity of the vessel wall was normal in all cases. This seems to be the first family in which there is evidence of an inherited abnormal fibrinolytic activity.

Adolescent

[Non-enzymatic fibrinolytic agents].

Non-enzyme fibrinolytic agents include pharmacological agents which are active in vivo but inactive in vitro and synthetic chemical compounds which when added to blood or plasma in vitro directly induce fibrinolysis. There are a number of drugs with a short duration of action such as adrenalin, nicotinic acid, vasopressin and histamine. Vasoactive drugs probably act by stimulating the liberation of vascular activator. The effect of nicotinic acid is rapidly exhausted when injections are repeated. By contrast, the biguanides and certain anabolic steroids are capable of exerting a long term stimulation of endogenous fibrinolysis. Amongst these substances, phenformin, metformin, ethyloestrenol, stanozolol and a new substance, moroxydine chloride, have been studied. The biguanides appear to be capable of exerting an effect upon the synthesis and liberation of plasminogen vascular activator. The combination of an anabolic steroid and a biguanide would appear to be the most powerful. These various drugs have been used with success in cases of recurrent venous thrombosis in patients with an abnormally low level of plasminogen activator in the venous walls and/or low fibrinolytic activity after venous stasis. Chemical fibrinolytic agents were studied only in vitro, since the use of these substances in human therapeutics would seem to be still difficult in view of the fact that they are active only in a narrow range of concentrations.

Anabolic Agents

Massive thrombosis of the superior mesenteric, splenic, and portal veins. Report of a case.

A 19-year-old previously healthy youth developed a deep venous thrombosis and a pulmonary embolism in connection with rupture of a ligament of the left ankle. Two months later, while on effective (thrombotest value 21%) oral anticoagulant therapy, the patient had massive thrombosis of the superior mesenteric splenic and portal veins and died. There was no known predisposition to thrombosis, such as tumour, infection, or trauma. A later examination of a 12-year-old brother revealed decreased fibrinolytic activity in the vessel wall as well as a decreased fibrinolytic response to venous occlusion. Since decreased fibrinolytic activity in the vessel wall is sometimes familial, it seems reasonable to suspect that the same defect might have occurred in the patient with the fatal massive thromboembolic disease.

Adult

Effects of porcine plasmin on the coagulation and fibrinolytic systems in humans.

Pig plasmin (Lysofibrin) was given to 11 patients with phlebographically verified venous thrombosis, 2 of whom were treated two and three times, respectively. The effect on coagulation and fibrinolytic parameters was studied. The platelet count, Owren's P&P (prothrombin plus factors VII and X), plasminogen, factor XIII, and antithrombin III did not change during the treatment. All patients developed a proteolytic activity demonstrable on both unheated and heated fibrin plates. The fibrinogen decreased successively to very low levels, and parallel to this an increase in fibrin/fibrinogen degradation products was found. The factor VIII and factor V activities decreased immediately after each Lysofibrin infusion but normalized rapidly again. The factor VIII molecule, however, retained its reactivity to rabbit antiserum against factor VIII. Immediately after the plasmin infusion a decrease of both alpha2-macroglobulin (alpha2-M) and the rapidly reacting alpha2-antiplasmin was observed. alpha2-M decreased successively and in several of the patients values were unmeasurable for a period of some days. A complex formation between pig plasmin and the alpha2-antiplasmin was demonstrated in crossed immunoelectrophoresis. The complexes were rapidly cleared from the circulation. No interaction between the pig plasmin and the inhibitor of the plasminogen activation, alpha1-antitrypsin or inter-alpha-inhibitor, was found.

Adult

Surgery of hemophiliacs--20 years' experience.

Seventy-seven hemophilic patients of type A or type B were subjected to a total of 108 major surgical procedures mainly in the field of general surgery, orthopedic surgery, or neurosurgery. The principles for the substitution therapy in the different types of procedures and different types of hemophilic diseases are described, as well as the indications for surgery and the surgical technique. The importance of prolonged substitution therapy postoperatively to avoid late hematoma, particularly in patients with severe hemophilia undergoing major surgery, is stressed. With this type of management there has been no increased intraoperative hemorrhage, and very few cases of late hematoma formation. By combining the substitution therapy with immunosuppression, it has been possible to operate also on patients with inhibitors against factor VIII or IX. The rate of complications, particularly the incidence of hepatitis, has been low with the type of substitution given in this series of patients. It is concluded that major surgery can be carried out even in severe hemophilia without significantly increased risk. The handling of the substitution therapy, and the surgical judgment and technique, offers however, special problems, necessitating centralization of elective cases.

Adolescent

Factor XIII (fibrin stabilising factor) in Henoch-Schönlein's purpura.

In 13 out of 17 consecutive children with Henoch-Schönlein's purpura the factor XIII determined with the dansyl cadaverine method was found to be decreased during the acute phase. The decrease is assumed to be due to a specific degradation by proteolytic enzymes liberated from inflammatory cells, with defective local haemostasis as a result. This assumption is strengthened by the observation that treatment with factor XIII combined with an antifibrinolytic drug controlled life-threatening gastro-intestinal bleeding in one of the patients. It would therefore appear that such treatment might offer a new possibility of controlling severe haemorrhages in Henoch-Schönlein's purpura.

Adolescent

Earlier and concurrent morbidity of patients with acute lower leg thrombosis.

The morbidity of 143 patients aged 15-55 years suffering from lower leg thrombosis had been analysed and compared with that of a control material. Ninety-two per cent of the patients suffering from thrombosis had earlier undergone some form of medical care at the hospital. The corresponding figure for the control material was 56%. Of the patients, 6% had a malignant disease, 24% were postoperative, 8% had trauma or fracture of the thrombotic leg, 18% had defects in the fibrinolytic system (58% of those in whom the fibrinolytic defence mechanism was studied), 20% were alcoholics or drug addicts, 15% (31% of the females) had used oral contraceptives, 15% had had an earlier thrombosis of the leg, and 8% of the patients had been in bed with some innocuous disease. It was concluded that a thrombosis often arises in patients with a high earlier morbidity and that most often two or more different conditions may predispose the patients to the disease.

Acute Disease

Effect of dextran and induced thrombocytopenia on the lysability of ex vivo thrombi in dogs.

The lysability of thrombi and clots was studied in intact and thrombocytopenic dogs. The thrombi were formed in ex vivo in rotating. Chandler loops, the clots were formed in plastic tubes. Infustion of dextran 70 to the intact dogs was followed by a significant increase in the lysability of the thrombi but not of the clots. Thrombocytopenia caused an increase in the lysability of both thrombi and clots. After infusion of dextran to thrombocytopenic dogs a further increase was noted in the lysability of thrombi but not of clots. The results indicate that dextran and induced thrombocytopenia increase the lysability of thrombi by different mechanisms. The different behaviour between thrombi and clots is probably due to the difference in structure between them particularly with regard to the distribution of platelets. It is suggested that dextran decreased the thrombus statility by impairing the platelet surface function.

Animals

Effect of ethyloestrenol on fibrinolysis in the vessel wall.

Forty-nine patients with decreased fibrinolytic activity in the vessel walls or a decreased release mechanism, or both, were treated with ethyloestrenol for three to 17 months. Forty-five of the patients had had recurrent, phlebographically verified, deep venous thrombosis (DVT) and four had arterial thrombosis. Ethyloestrenol 8 mg/day was given to 31 patients and 4 mg/day was given to 12. The remaining six patients had been treated with a combination of phenformin and ethloestrenol. The phenformin was withdrawn but they were kept on ethyloestrenol 8 mg/day. Another 15 patients with a normal fibrinolytic system--four with recurrent DVT and 11 with severe arteriosclerosis--were given ethyloestrenol 8 mg/day. The spontaneous fibrinolytic activity, local fibrinolytic activity during standardised venous occlusion of the arms, and fibrinolytic activity of the vessel walls increased significantly after treatment with ethyloestrenol 8 mg/day for three months. No further increase occurred after three months, and ethyloestrenol 4 mg/day had no effect. No values rose significantly in the patients with a normal fibrinolytic system. One patient suffered a recurrence within three months of treatment, before the fibrinolytic system became normal. In one patient the fibrinolytic defect reappeared after 10 months in spite of continued treatment. Two of the three women of fertile age developed irregular cycles and intermenstrual bleeding, which disappeared when the treatment was withdrawn. No other side effects were observed.

Adult

Various prothrombin complex concentrates and their effect on coagulation and fibrinolysis in vivo.

Thromboembolic complications occurring in patients treated with factor IX concentrates have been reported. To study the thrombogenicity various types of factor IX concentrates (50 or 100 units F. IX/kg bodyweight) have been infused in dogs. As control albumin was given. The various components of the coagulation and fibrinolytic system have been assayed before the infusion and at various intervals after the end of infusion (0, 1, 4 and 24 hrs). Konyne resulted in marked activation of the coagulation process with decrease of platelets, fibrinogen, F. VIII and appearance of FDP and positive ethanol gelation test. Prothromplex and Preconativ gave no significant changes. Preconativ is prepared without addition of heparin during the procedure.

Animals

Immunosuppressive treatment in haemophiliacs with inhibitors to factor VIII and factor IX.

9 patients with severe haemophilia A and inhibitors (inhibitor levels between 0.1 to 5.8 U/ml) and 3 patients with severe haemophilia B and inhibitors (inhibitor levels between 0.1 to 11 U/ml) were treated on a total of 16 and 13 occasions, respectively, with a large dose of antigen (factor VIII or factor IX) and cyclophosphamide (10-15 mg/kg b.w. i.v. initially and then 2-3 mg/kg b.w. orally for 7-10 days) in connection with severe bleeding and surgery. All the patients had proved not to respond to treatment with factor VIII or factor IX concentrate alone, and all except one had shown strong secondary antibody increases. In 6 of the patients with haemophilia A the treatment (11 occasions) had a satisfactory haemostatic effect and even permitted neurosurgery without bleeding complications. The inhibitor level remained at zero for 5-10 days, after which it gradually began to return towards its original level. In these cases it was possible to give factor VIII in amounts which neutralised the inhibitor and afterwards raised the factor VIII initially to at least 50%. In the 3 patients with haemophilia B treatment (13 occasions) was successful except on one occasion, and surgery was performed without abnormal bleeding. The factor IX level was initially raised to at least 50% except in the one failure. The inhibitor level remained at zero for 12 days to 3 months, after which it gradually rose towards its original level. One patient was treated on 8 occasions.

Adolescent

Haemophilia prophylaxis in Sweden.

29 boys (4-18 years old) with severe haemophilia A were given prophylactic infusions of AHF concentrate (human fraction I-0) for 2 to 13 years in an attempt to change the haemophilia from a severe to a moderate form and thereby prevent arthropathy and severe bleeding episodes. The sizes of the doses and the intervals at which the doses were given were titrated by AHF survival studies. As a rule, the patients received AHF in amounts sufficient to raise the AHF level to 30-45% at 5-12 day intervals. In about 50% of the infusions the AHF content was not below 1% before the next infusion. During such prophylaxis all patients except one have been in a good general condition. They have had bleeding episodes, which have, however, been much less severe and less frequent. The children have been able to live an almost normal life. The number and duration of stays in hospital have been markedly reduced. 17 of the patients had only minor or no joint defects before the start of the treatment. In this group the joint function was identical with that found in moderate haemophilia in the same age groups. Two patients developed anticoagulants. No other side effects were seen. The prophylactic regimen in Sweden thus reduced severe haemophilia to moderate.

Adolescent