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Biomedical subjects

D Bergqvist

Publications and source records attributed to D Bergqvist.

At least 505 records · Page 28Linked to original sources
PubMed1984

Human ureter, a source of tissue plasminogen activator.

In organ cultures of human ureters, plasminogen activators were released into the medium. Unlike most tissue cultures that release mainly urokinase (UK), the activators released by ureter cultures were predominantly of the tissue-type (t-PA), as shown by radioimmunoassay. Using affinity chromatography it was possible to distinguish two activities. One minor fraction was quenched by antibodies against UK, but not by antibodies against t-PA. The other activity was quenched by antibodies against t-PA, but not by those against UK, and required the presence of fibrin to activate plasminogen. Because of the large amount of t-PA, cells derived from human ureter might well prove to be a useful source of t-PA.

Adolescent↗
PubMed1984

Thromboxane production in umbilical vein grafts.

Umbilical vein grafts were placed in the carotid arteries of sheep and removed after 10 or 90 days for determination of in vitro production of 6-keto-PGF1 alpha and thromboxane B2 (TxB2) in the anastomoses and in the middle of the grafts. At both intervals the grafts produced much more TxB2 than carotid arteries, but no significant difference in production of 6-keto-PGF1 alpha was found between grafts and carotid arteries. The strongly decreased 6-keto-PGF1 alpha/TxB2 ratio indicates a low resistance to platelet adhesion and aggregation, which may be a contributory cause of the thrombogenicity of vascular grafts and may possibly be involved in the pathogenesis of neointimal fibrous hyperplasia.

6-Ketoprostaglandin F1 alpha↗
PubMed1984

The thromboprophylactic effect of graded elastic compression stockings in combination with dextran 70.

We studied 80 patients who were older than 50 years of age to determine if graded elastic compression stockings reduced the frequency of postoperative thrombosis in patients undergoing dextran 70 prophylaxis. All of the patients received a total of 2,000 mL of dextran 70 during three days; according to a random table, each of the patients had one leg encased in a graded compression stocking for one week. Thrombosis development was screened with the fibrinogen I 125 test. Eight patients manifested thrombosis-one in the thigh and seven in the calf--localized to the unstockinged leg, a frequency significantly greater than the zero frequency in the stockinged leg. No untoward effects of this combination prophylaxis were noted.

Aged↗
PubMed1984

Deep venous insufficiency after postoperative thrombosis diagnosed with 125I-labelled fibrinogen uptake test.

Postoperative thrombosis detected with the 125I-labelled fibrinogen uptake test (FUT) is frequent. FUT correlates well with phlebography and a positive FUT is associated with high incidence of pulmonary embolism. This study has been performed to evaluate venous function 3-5 years after FUT-detected thrombosis. A follow-up examination was performed in 381 patients who had been studied after operation with FUT. The follow-up included a questionnaire, clinical examination, venous occlusion strain-gauge plethysmography, ambulatory strain-gauge plethysmography, venous pressure examination and, in some cases, Doppler ultrasound examination of venous valve function in the leg. No statistically significant differences were found in any parameters used between legs with and without FUT-detected postoperative thrombosis, except that more FUT-positive legs had an abnormal venous pressure decrease during exercise than FUT-negative legs. The frequency of deep venous insufficiency was equal in FUT-positive and FUT-negative legs. Moreover the frequency of deep venous insufficiency was not affected by the site of the FUT-detected thrombosis or by the different kinds of prophylactics used. The frequency of venous insufficiency was high.

Aged↗
PubMed1984

Does dihydroergotamine potentiate the thromboprophylactic effect of dextran 70? A controlled prospective study in general and hip surgery.

In a prospective randomized controlled study on postoperative thromboembolism, 259 patients undergoing elective general surgery, emergency general surgery, total hip replacement or hip fracture surgery were given thromboembolic prophylaxis with either a combination of dextran 70 and dihydroergotamine (DHE) or with dextran 70 alone. 500 ml dextran 70 was infused twice on the day of operation, once on postoperative days 1 and 3, and also on day 5 if the patient was still confined to bed. 0.5 mg DHE was given s.c. twice daily starting before operation and continued for 3 or 5 postoperative days. In hip fracture patients prophylaxis was started as soon as the diagnosis was made. 500 ml dextran 70 was given every other day before operation. DHE was given twice daily if so indicated from randomization. The patients were screened for deep-vein thrombosis (DVT) with the 125I-labelled fibrinogen test for 8 days and followed for one month postoperatively. In hip fracture surgery the incidence of DVT was significantly reduced by the combination of dextran 70 and DHE compared to dextran 70 alone (1/32 vs. 11/36, P = 0.003). However, this synergistic effect of DHE could not be detected in the other patient groups. Fatal pulmonary embolism did not occur. No severe side effects attributable to prophylaxis were noted in either group.

Aged↗
PubMed1984

Decreased fibrinolytic activity in human atherosclerotic vessels.

Using a semi-quantitative, histochemical fibrin slide technique, plasminogen activator (PA) activity was determined in 65 atherosclerotic arteries obtained from 65 patients during surgery -42 during resection of the infrarenal part of the aorta, and 23 from a leg artery in patients undergoing a below-knee amputation. In 12 of the patients undergoing resection of the aorta, another specimen was obtained from a collateral artery free from atherosclerotic lesions. PA activity in the atherosclerotic aortic specimens was significantly decreased compared with that in collateral arteries, and low PA activity was also found in leg arteries.

Adult↗
PubMed1984

Effects of dihydroergotamine on the feline cardiovascular response to intravenous infusion of live Escherichia coli bacteria.

A septic shock state was induced in cats by intravenous infusion of live Escherichia coli bacteria. Cats pretreated with an unspecific 5-HT blocker, dihydroergotamine (DHE), or with a specific 5-HT blocker, ketanserin, were compared with a series receiving bacteria without pretreatment. DHE pretreatment prevented the reduction in systemic arterial blood pressure found in the other series during the 2-hour period of septic shock. Pretreatment could not influence the increased vascular resistance in the pulmonary vascular bed or the early increase in pulmonary arterial blood pressure. Peripheral blood flow distribution was studied using radioactive labelled microspheres. Compared to bacteremia without pretreatment, the 5-HT blockers increased CNS blood flow and ketanserin also prevented the reduction in pancreatic blood flow. Gastric blood flow and gastric mucosal blood flow remained unchanged in all series as did the small intestinal total blood flow. Small intestinal mucosal blood flow, however, was reduced after 2 h of bacteremia. Microscopy revealed no gastric epithelial damage while the jejunal mucosa was characteristically damaged. There was no correlation between the changes in the small intestinal blood flow and the degree of mucosal damage, however, supporting the countercurrent theory for the pathogenesis of these lesions.

Animals↗
PubMed1984

The role of the prostanoid system in mediating the haemodynamic effects of dihydroergotamine.

Dihydroergotamine (DHE) increases tonus in veins, especially in capacitance vessels, thereby reducing blood pooling and increasing venous blood flow velocity and it has been suggested that DHE achieves its effect partially through its influence on prostanoids synthesis and release. Pretreatment with indomethacin did not affect DHE response in central haemodynamic variables or in tissue blood flow in dogs; nor did it affect the reduced venous vessel area, increased blood flow in dogs; nor did it affect the reduced venous vessel area, increased venous blood flow velocity (measured ultrasonically), or reduced resting calf volume blood flow (measured by plethysmography), caused by DHE in humans. Although the number of animals and of humans in this study were small, nontheless it seems unlikely that the effect of clinically relevant doses of DHE is appreciably mediated by the prostanoid system.

Animals↗
PubMed1984

Postoperative haemostatic changes in patients given thromboembolic prophylaxis with dextran 70--alone, or in combination with dihydroergotamine.

Haemostatic changes were studied in 107 patients undergoing elective general and urologic surgery or hip replacement. All patients received dextran 70 and half of them, randomly chosen, were also given dihydroergotamine. Blood samples were taken before operation and on the fourth postoperative day. In all patients increases in factor VIII:C, VIII:R Ag and fibrinogen were noted, and decreases in thrombin time, antithrombin III and alpha 2-macroglobulin. In patients undergoing hip replacement, alpha 2-antiplasmin (measured amidolytically) also increased. No major intergroup differences were noted. Comparison between elective hip patients given general anaesthesia and those given epidural analgesia revealed no major differences in haemostatic response. From our findings it would appear that the coagulation and fibrinolytic systems remain unaffected by dihydroergotamine.

Aged↗
PubMed1984

Effect of heparin, low molecular weight (LMW) heparin, and a heparin analogue on experimental venous thrombosis in the rabbit.

An experimental model based on a combination of endothelial injury and flow reduction, was used to induce jugular vein thrombosis in the rabbit. The influence of conventional heparin, a low molecular weight fragment (LMW heparin; M.W. 4 000-5 000) and a heparin analogue (sodium pentosan polysulfate) was compared. The drugs were administered intravenously during the induction of thrombosis. The control animals received Ringer's lactate. All treatments significantly reduced the frequency of thrombosis. In addition, LMW heparin caused a significant reduction of thrombus weight. Moreover, it was shown that local treatment with conventional heparin and LMW heparin after endothelial damage both reduced the frequency of thrombosis.

Animals↗
PubMed1984

The efficacy of dextran 40 in preventing early postoperative thrombosis following difficult lower extremity bypass.

In a randomized, multicenter trial the efficacy of intravenous dextran 40 (D-40; Rheomacrodex) in preventing early postoperative thrombosis was tested in the following difficult lower extremity bypasses: (1) femoropopliteal with poor runoff using autologous vein (AV), (2) femoropopliteal using grafts other than AV, (3) single or sequential bypasses to infrapopliteal arteries, and (4) the above-mentioned bypasses with adjunctive procedures that destroy adjacent endothelial surfaces (e.g., thrombectomy and endarterectomy). Five units of D-40 was administered to the experimental group at 75 to 100 ml/hr, two during and immediately after operation and one each 3 days postoperatively. Antiplatelet drugs were withheld until 1 week after surgery. The overall 1-week occlusion rate was 6.9% (5 of 73) with D-40 and 20.5% (17 of 83) for controls, which is statistically significant. Particularly significant was the difference in group 3: 0% (0 of 28) for D-40 and 27.8% (10 of 36) for controls. In the same time period there were no occlusions in group I and only one occlusion each with AV grafts in both D-40 and control groups, 2.6% (1 of 38). When grafts other than AV were used, the occlusion rate was significantly lower at 1 week for D-40, 11.4% (4 of 35), than controls, 35.6% (16 of 45). By 1 month the protective effect of D-40 was partially lost--15.3% (11 of 72) for D-40 and 20.7% (17 of 82) for controls (no statistical significance). Use of antiplatelet drugs during this period had no discernible effect.

Blood Vessel Prosthesis↗
PubMed1984

Reversible renal insufficiency after percutaneous transluminal angioplasty (PTA) of renal artery stenosis.

Three patients developed reversible renal insufficiency after successfully performed PTA at the same time as their hypertension was beneficially influenced. The main cause of this complication probably is toxic effects of contrast medium in combination with the temporary occlusion of the renal artery during the PTA of kidneys with previously damaged parenchymal and impaired perfusion. During the phase of renal insufficiency contrast medium retention in the renal cortex was noted at computed tomography.

Acute Kidney Injury↗