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Biomedical subjects

D Bergqvist

Publications and source records attributed to D Bergqvist.

At least 451 records · Page 25Linked to original sources
PubMed1986

Heparin-induced osteoporosis in rats.

In order to study the effect of heparin in inducing osteoporosis, 30 female rats were divided in two groups and treated with daily injections of 2 IU heparin/g body weight for 33 and 65 days and compared with the same number of rats acting as controls. The mineral bone mass in the femora of the animals was measured quantitatively. A significant (p less than 0.001) reduction in bone mineral mass was found in the heparin-treated animals. This effect was present to the same degree after 33 days as after 65 days of treatment. It is concluded that heparin in this dose causes osteoporosis in rats after 33 days and that the described method can be used as an experimental model for further studies on this topic.

Animals↗
PubMed1986

The influence of ketanserin on hemostasis in vitro.

Ketanserin is a new selective 5-HT2 receptor blocker. It has been used to indirectly study the influence of serotonin on hemostatic function in vitro. Coagulation and fibrinolysis in vitro were not affected. In high doses adrenalin induced platelet aggregation was inhibited but no influence was seen on collagen or ADP induced aggregation. It can be concluded that it is not very likely that serotonin plays an important role in initial hemostasis. However, the findings ought to be confirmed in vivo.

Adenosine Diphosphate↗
PubMed1986

Thrombin uptake and inhibition on heparinized polytetrafluoroethylene (PTFE) grafts and native sheep vessels.

Non-heparinized and covalently-heparinized PTFE grafts, sheep aorta, carotid artery and jugular vein were evaluated according to their ability to adsorb and inactivate thrombin. All surfaces, except non-heparinized PTFE caused considerable losses of enzymatically active thrombin from the solution. Covalently-heparinized PTFE and jugular veins adsorbed thrombin, which was inactivated on subsequent contact with antithrombin III. Despite the same loss from the solution as was encountered with veins arteries adsorbed significantly smaller amounts of thrombin. Protamine treatment of covalently-heparinized PTFE almost totally abolished the ability to adsorb thrombin. It is concluded that 1) arteries possess a stronger thrombin inhibitory capacity than veins, possible explanations to this being a different glucosaminoglycan or the presence of antithrombin III in the arterial wall and 2) that heparinizing PTFE results in a pronounced ability to inactivate thrombin.

Animals↗
PubMed1986

Small bowel necrosis after aorto-iliac reconstruction.

Small bowel ischaemia causing necrosis is a rare complication after aorto-iliac reconstructive surgery. During a 14-year-period we have seen 6 cases out of 1343 reconstructions, making a frequency of 0.4 per cent. Diagnosis was difficult, causing a delay until re-exploration. Thrombocytopenia was a constant finding, and should raise suspicion. Pathogenesis was multifactorial. In two of our cases diagnosis was made at autopsy and in four at operation. Two patients survived extensive bowel resection but had a long stormy postoperative course.

Adult↗
PubMed1986

Low molecular weight heparin once daily compared with conventional low-dose heparin twice daily. A prospective double-blind multicentre trial on prevention of postoperative thrombosis.

In a randomized, prospective, double-blind multicentre trial, the effect of conventional low-dose heparin 5000 units twice daily, was compared with that of a low molecular weight heparin fragment (4000-5000) 5000 anti-factor Xa units once daily. Four hundred and thirty-two patients fulfilled the inclusion criteria and were analysed for development of deep vein thrombosis (125I-labelled fibrinogen test) and haemorrhagic complications. Thrombosis occurred in a 4.3 per cent of patients in the low-dose heparin group and in 6.4 per cent of patients in the heparin fragment group, a difference which is not significant. There was a significant delay in the onset of thrombosis in the heparin fragment group. Mortality did not differ between the groups, nor did peroperative blood loss or transfusion requirements or infectious complications. Haemorrhagic complications occurred significantly more often in the fragment group (11.6 per cent) than in the conventional heparin group (4.6 per cent). Patients in the heparin fragment group experienced local pain following the subcutaneous injection significantly less often.

Adult↗
PubMed1986

Does dihydroergotamine reduce plasma volume?

Indications on a plasma volume reduction by dihydroergotamine (DHE) has been found in earlier studies. This study was made in order to further evaluate such a change. In animal experiments (sheep, n = 10) measurements were performed of red blood cell volume and plasma volume using radioactive labelling techniques. Red blood cell volume was unchanged but a plasma volume decrease of 10% was found after two hours and it persisted for 24 hours. In postoperative patients (n = 9), who had been given an infusion of ringer-glucose (5.5%) at a rate of 100 ml/hour, DHE caused an increase in diuresis but neither ADH (n = 9) nor aldosterone (n = 3) levels were changed. The data from the present study further support the earlier findings of a reduced plasma volume after DHE administration. The main effect of dihydroergotamine is on the vascular bed and especially on capacitance vessels (increased tonus). The reduced plasma volume by DHE seems to be one additional effect of DHE.

Aldosterone↗
PubMed1986

Heparin and its low molecular weight derivatives: anticoagulant and antithrombotic properties.

The anticoagulant and antithrombotic effect of heparin has been known for many decades. Nevertheless, the knowledge of structure-activity relationships and its mechanisms of action has been rather limited. However, in recent years important progress has been made and our understanding of how heparin works has increased significantly. Based on this information, attempts have been made to modify heparin to get improved pharmacological properties. The present communication summarizes the recent development. It is shown that certain heparin derivatives of low molecular weight are highly interesting compounds from a clinical point of view. Biochemical and pharmacological properties of such a preparation named Fragmin are presented.

Blood Coagulation↗
PubMed1986

Prospective double-blind comparison between Fragmin and conventional low-dose heparin: thromboprophylactic effect and bleeding complications.

In a randomized, prospective, double-blind multicenter trial, the effect of low-dose conventional heparin (5,000 IU/12 h) was compared to a low molecular weight (LMW) heparin fragment (5,000 antifactor Xa U/24 h). 432 patients 40 years or older undergoing elective abdominal surgery were included, 382 correctly treated. 45% had malignant diseases. The groups did not differ in risk factors. Analysis was made both on the basis of intention to treat and correct prophylaxis. No difference in results between these 2 groups was seen. Deep vein thrombosis (125I-fibrinogen) occurred in 4.3% of the low-dose heparin group and in 6.4 of the LMW heparin group. There was a significant delay in the onset of deep vein thrombosis in the LMW heparin group. Mortality, peroperative blood loss, transfusions or infectious complications did not differ. Hemorrhagic complications occurred significantly more often in the LMW heparin group (11.6%) than in the low-dose heparin group (4.6%). Significantly fewer patients experienced local injection pain in the LMW heparin group. APTT and AT III were similar in both groups, but anti-Xa activity was significantly higher in the LMW heparin group. Single daily LMW heparin injection reduced the frequency of deep vein thrombosis to the same level as low-dose heparin twice daily. The dose or administration interval of LMW heparin in this study caused significantly more bleeding complications.

Aged↗
PubMed1986

Doppler spectral analysis of the internal carotid before and after endarterectomy.

In 37 randomly selected patients, stenosis of the internal carotid artery was evaluated with Doppler spectral analysis before and 6-10 weeks after endarterectomy. Postoperatively 20 of the vessels were entirely within the normal variation range and four, though not normal, showed significantly lower blood flow velocity, indicating wider vascular lumen. In ten cases there were no significant postoperative change, and in three significant worsening of the Doppler shift was seen without clinical implications. The method is useful for evaluating the endarterectomized carotid noninvasively without use of contrast medium, and when bilateral operation is contemplated the analysis is most valuable for ruling out occlusion in the artery first operated on.

Aged↗
PubMed1986

The acute thrombogenicity of a compliant polyurethane arterial graft compared with autologous vein. An experimental study in sheep.

The acute thrombogenicity of a new type of polyurethane urea graft was compared with that of autologous femoral vein graft in a sheep carotid artery interposition model. There was significantly more thrombus formation (as measured from thrombus weight and thrombus-free surface) and greater platelet accumulation in the polyurethane graft. Despite flow restriction to 25 ml/min, the patency rates after 4 hours were similar; all veins were patent and only one of the eight polyurethane grafts was occluded.

Animals↗
PubMed1986

The Mallory-Weiss syndrome. An analysis of haemostatic function in a bleeding-free period.

The bleeding source in the Mallory-Weiss syndrome is mucosal tears at the gastro-oesophageal junction. It has been suggested that haemostatic defects play an active role in the syndrome's development. This study was made to analyze whether or not such defects are present during a bleeding-free period following the Mallory-Weiss syndrome. Fourteen patients were examined 4 weeks to 5.8 years after the bleeding episode. In most cases the coagulation mechanism was then found to be normal. Mild haemostatic defects were found in four patients, but were not of consistent type.

Adult↗
PubMed1986

Late venous function in the leg after deep venous thrombosis occurring in relation to pregnancy.

The frequency of deep venous insufficiency was investigated in 23 patients 3-10 years (mean 7 years) after they had developed an objectively diagnosed deep venous thrombosis (DVT) during pregnancy or the first week after delivery. Investigations included clinical examination, listing of symptoms and plethysmography, venous pressure and Doppler ultrasound. At follow-up there were clinical signs or symptoms of venous insufficiency in 35% of the legs with earlier DVT but in none of the non-thrombosed contralateral legs. Objective evidence of venous insufficiency was present in 15 (65%) of the legs with earlier DVT and in only five (22%) of the non-thrombosed legs. The differences between thrombosed and non-thrombosed legs are statistically significant. There was no correlation between objectively measured venous insufficiency and extent of the DVT. It is concluded that a DVT during pregnancy often leads to venous insufficiency and the risk seems to be higher than after DVT occurring in other groups of patients.

Adolescent↗