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Biomedical subjects

D Bergqvist

Publications and source records attributed to D Bergqvist.

At least 235 records · Page 13Linked to original sources
PubMed1994

Antithrombotic effect of recombinant truncated tissue factor pathway inhibitor (TFPI1-161) in experimental venous thrombosis--a comparison with low molecular weight heparin.

The aim was to investigate whether a truncated recombinant Tissue Factor Pathway Inhibitor (TFPI1-161), which lacked the third Kunitz-type domain and the basic c-terminal region, had an antithrombotic effect comparable to LMWH in a randomised double-dummy study. The experimental thrombosis was induced in jugular veins, in a total of 40 rabbits by a combination of destruction of the endothelium and restricted blood flow. Group 1: placebo, gr 2: LMWH 60 anti-FXa IU/kg, gr 3-5: 0.1, 1.0 and 10.0 mg/kg TFPI1-161. TFPI1-161 reduced the thrombus weights in all treated groups, significantly in doses of 1.0 and 10.0 mg/kg compared to placebo. The frequency of thrombosis and occlusive thrombosis were also significantly reduced in those doses. The antithrombotic properties of TFPI1-161 (1.0-10.0 mg/kg) measured as thrombus weight, frequency of thrombosis and frequency of occlusive thrombosis was equivalent to the anti-thrombotic properties of LMWH. In the anti-FXa, APTT and PT-assays TFPI1-161 displayed a dose dependent increase of activity. Recombinant-TFPI1-161 did not influence the anti-FIIa-assay. No haemorrhagic side effects were noted.

Animals↗
PubMed1993

Natural history of abdominal aortic aneurysm detected by screening.

A group of 88 patients with abdominal aortic dilation found in four ultrasonographic screening studies was followed prospectively by repeated ultrasonography. The initial aortic diameter ranged between 18 and 70 mm. In 19 patients (22 per cent) the aortic diameter exceeded 39 mm. The mean (s.e.m.) annual expansion rate of dilatations < 40 mm in diameter was 0.8 (1.2) mm; among those > or = 40 mm it was 3.3 (1.2) mm. The expansion rate increased with increasing initial diameter. Thirty-eight patients died; the overall mortality rate in the group was high in comparison with an age- and sex-matched population. One patient died after elective aneurysm surgery but none died from a ruptured aneurysm. In conclusion, in about 80 per cent of dilatations found in screening studies the aortic diameter was < 40 mm, with a low risk of rupture. One annual rescanning of an aneurysm < 35 mm in diameter is sufficient; a high overall mortality rate must be expected.

Aged↗
PubMed1993

Endothelin does not contribute to the vasospasm after balloon angioplasty in vitro.

The present study was undertaken in 43 rabbits to determine whether endothelin or potassium are mediating substances for vasospasm originating from the vessel wall after balloon angioplasty. Thirteen aortic segments were dilated and the luminal surfaces perfused. These perfusates were investigated for their vasomotor action per se and analyzed for their concentrations of potassium and endothelin-like immunoreactivity (ET-LI). The perfusates from angioplasty segments caused a contraction of 2.4 +/- 0.8 mN, while the perfusates from control segments only resulted in a contraction of 0.4 +/- 0.2 mN, (P = 0.004). There was no difference in the concentrations of potassium or ET-LI in the perfusates. Thirty aortic segments were used to measure the concentration of ET-LI in extractions of untreated, control, and angioplasty specimens. There was no statistically significant difference between the groups. Scanning electron microscopy demonstrated the angioplasty segments to be denuded of their endothelium. In conclusion, perfusates from rabbit aortic segments treated by angioplasty in vitro have a strong vasoconstricting effect, for which neither endothelin nor potassium seems to be responsible.

Angioplasty, Balloon↗
PubMed1993

The effect of cyclosporine A dissolved in chremofore or in ethanol and of cortisone on the arterial release of prostacyclin.

Cyclosporine A has been suggested to increase thromboembolic complications after renal transplantation. Therefore, the effect of cyclosporine A (at the clinically used dose of 10 mg/kg) dissolved in either chremofore or ethanol on rabbit vascular prostacyclin release was investigated in an ex vivo perfusion system. The animals received the drugs intravenously either as a single injection the day before operation or daily for 1 month prior to operation. Rabbits given cyclosporine A dissolved in chremofore released less prostacyclin than controls, both after a single injection and after 1 month of daily injections. The vehicle chremofore also gave a significantly lower release of prostacyclin than the control. The response to arachidonic acid with increased release was equal in all groups. Cyclosporine A dissolved in ethanol did not alter the initial release, and ethanol alone did not influence the prostacyclin release. Cortisone depressed the vascular prostacyclin release after daily injections for 1 month, but did not after only one injection. Cyclosporine A dissolved in chremofore and cortisone given in combination did not result in an additive reduction. These findings indicate that the intravenous administration of cyclosporine A dissolved in chremofore, but not that dissolved in ethanol, as well as cortisone, might decrease the vascular defense against thrombus formation. The action of these substances is higher up in the arachidonic acid cascade than the cyclooxygenase level.

6-Ketoprostaglandin F1 alpha↗
PubMed1993

Blood flow velocity in the middle cerebral artery and carotid artery stump pressure during carotid endarterectomy.

Twenty-one patients undergoing carotid endarterectomy were investigated by simultaneous intra-operative measurements of carotid stump pressure (CSP) and transcranial Doppler (TCD) flow velocity in the middle cerebral artery. The relationship between the two methods was evaluated as well as the potential benefits of the intraoperative transcranial Doppler monitoring technique. Clamping of the carotid artery resulted in a significant decrease in TCD flow velocity in the ipsilateral middle cerebral artery as well as in CSP. There was no correlation between relative change in CSP and the simultaneously obtained relative change in TCD flow velocity during carotid clamping (r = 0.31, p = 0.26). The insertion of an intra-operative shunt was followed by an increase in flow velocity compared to the clamping value. One patient with clear TCD signs of a re-occlusion (a sudden decrease in flow velocity) during closure of the wound, demonstrated a thrombosis at re-exploration. TCD gives information of the collateral cerebral circulation during carotid clamping and is an alternative monitoring technique during carotid endarterectomy. The method is useful intraoperatively for detecting embolic events as well as thrombosis during wound closure. Further studies are necessary to clarify the critical change in flow velocity during clamping when the use of a peroperative shunt is indicated.

Aged↗
PubMed1993

Can recurrent stenosis after carotid endarterectomy be prevented by low-dose acetylsalicylic acid? A double-blind, randomised and placebo-controlled study.

Recurrent stenosis (> 50%) after carotid endarterectomy is reported with a frequency ranging from 7-20%. 232 patients undergoing carotid endarterectomy were randomised to low-dose acetylsalicylic acid (ASA, 75 mg daily) or placebo (identical tablets). The treatment was started the day before surgery and continued for 6 months. All patients were followed clinically for 1 year. Doppler examination was performed preoperatively (n = 230) and postoperatively (n = 228) and at follow-up at 2 (n = 220) and at 6 months (n = 174) after surgery. The degree of stenosis was estimated from the maximum Doppler frequency shift in the internal carotid artery. Recurrent stenosis of 30% or more was detected in 85 of the 220 patients (38.6%) at 2 months, and at 6 months in 73 of the 174 examined patients (42.0%). Stenosis > 50% was seen in 16 patients (9.2%) and occlusion was found in four patients (1.8%) at 6 months. No difference between the low-dose ASA-treated group (n = 112) compared to the placebo group (n = 108) was seen regarding recurrent stenosis. Women had an increased risk of recurrent stenosis (p < 0.001), whereas other factors such as age, hyperlipidaemia, diabetes and smoking were not associated with increased risk. Importantly, the number of neurological events did not differ between those with or without restenosis. Therefore, the indications for surgery of asymptomatic recurrent stenosis are questionable. The progress of arteriosclerosis in the contralateral carotid artery did not differ between the treatment groups.

Adult↗
PubMed1993

The choice of strategy in the treatment of intermittent claudication--a decision tree approach.

OBJECTIVES: to compare possible outcomes of the non-operative treatment for intermittent claudication with that of surgery. DESIGN: decision tree approach using published and vascular registry data. The valuation of clinical outcomes was estimated by index weights using the Rosser index and the Quality of Well-Being scale. SETTING: routine health care in Sweden. MATERIALS: published data on 224 non-operatively treated claudicants and data from 805 claudicants treated with surgery or angioplasty from the Swedvasc registry. No diabetics were included. Chief outcome measure: expected utility value at one year after decision on treatment given the clinical data and the estimated health status valuations. MAIN RESULTS: it was possible to identify a success rate for surgery above which it was the better alternative. However, depending on which of two health indices that was used, and if reconstruction was supra- or infrainguinal, this threshold value varied from 0-81%. CONCLUSIONS: reliable measures of the value of outcomes have to be developed and, in addition, long-term data on outcome and costs in routine care have to be collected before a comprehensive economic assessment based on the decision tree approach can be made to support decisions on treatment for intermittent claudication.

Aged↗
PubMed1993

The uptake of platelets, fibrinogen and leucocytes in ePTFE vascular grafts in relation to blood flow--an experimental study in sheep.

The uptake of platelets, fibrinogen and leucocytes in relation to blood flow was studied in ePTFE arterial grafts inserted in both common carotid arteries of 10 adult sheep. Autologous platelets labelled with In-111, autologous leucocytes labelled with Tc-99m and homologous fibrinogen labelled with I-125 were used. The leucocyte uptake was studied in five of the animals. The uptake was measured with a gamma scintillation technique. The blood flow in the graft on one side was restricted to 25 ml/mm, and in the other graft the blood flow was unrestricted (median 170 ml/min). One out of 10 grafts in the reduced flow group occluded but none of the grafts in the unrestricted flow group. The mean thrombus weight was significantly higher in the reduced unrestricted flow (0.28 vs. 0.19 g). At the proximal anastomosis the uptake of platelets, fibrinogen and leucocytes was higher in the reduced than unrestricted flow. The differences were significantly higher for fibrinogen for the whole duration of the experiments and for platelets and leucocytes during the last 48 min. Distally the platelet and fibrinogen uptake were higher in the reduced than in unrestricted flow. The leucocyte uptake did not differ distally. The differences were significant for fibrinogen for the whole duration of the experiments and for platelets during the last 120 min. A comparison between the proximal and distal anastomosis showed a higher uptake distally.

Animals↗
PubMed1993

Prediction of early graft occlusion in femoropopliteal and femorodistal reconstruction by measurement of volume flow with a transit time flowmeter and calculation of peripheral resistance.

A transit time flowmeter (Transonic TC101DTM, Transonic Inc., U.S.A.) was used for flow measurements and calculation of peripheral resistance in 48 primary femoropopliteal and femorodistal reconstructions. The results were correlated with primary graft occlusions during the first 90 postoperative days. There were 25 men and 23 women with a median age of 75 years (67-83). Eight were diabetic. Indications for surgery were rest pain (n = 23), ischaemic ulcer (n = 16), gangrene (n = 8) and popliteal aneurysm (n = 1). Measurements were made before reconstruction on the artery at the site of the distal anastomosis. After reconstruction flow measurements were made on the graft near the proximal and distal anastomoses together with a proximal graft pressure measurement. The peripheral resistance was calculated. Eleven grafts occluded and six patients died, four with patient grafts. Patients with graft occlusions had a significantly lower flow before (4 vs. 20 ml/min) and after (60 vs. 110 ml/min) reconstruction and a higher peripheral resistance, (1238 vs. 625 mPRU) than patients with patent grafts. The most significant differences were found in the femorodistal bypass grafts. The transit time flowmeter was easy to use. The flow before and after reconstruction as well as the peripheral resistance could be used for the prediction of graft function within 90 days of surgery.

Aged↗
PubMed1993

Natural history of patients with unoperated atherosclerotic carotid artery disease--results from a retrospective study.

The natural history of carotid artery disease was studied in a retrospective study of 609 angiograms performed during 1969-1979 on patients who had subsequently not been operated on. The indication for angiography differed, but was aimed at clarifying suspected cerebrovascular events. 578 patients could be followed-up after a median time of 10.4 years (0-22). The median survival time after angiography was 9.7 years for the 355 men and 12.8 years for the 223 women (p = 0.0099). Internal carotid stenosis of > 50% was seen in 9.0% (bilaterally in 2.2%), a stenosis > 75% in 4.5% (bilaterally in 0.9%) and occlusion in 9% (bilaterally in 0.7%). Ulceration was present in 10.7% (bilaterally in 1.6%). 26.5% of the patients had a cerebrovascular event during follow-up, of which 31.4% had transient ischaemic attack or amaurosis fugax. Survival was not influenced by the degree of stenosis, but presence of arteriosclerotic carotid artery disease significantly reduced the median survival time from 11 to 3 years. The main cause of death for men was myocardial infarction (27.7%) and for women a cerebrovascular event (27.8%), a significant difference. From this study, in selected patients it can be concluded that the annual frequency of cerebrovascular events was low, approaching frequencies reported in asymptomatic patients. The cause of death differed between men and women, with more cardiac deaths among men and more cerebrovascular deaths among women.

Carotid Artery Diseases↗
PubMed1993

Ruptured abdominal aortic aneurysm: a population-based study.

PURPOSE: The purpose of this study was to make an analysis of all ruptured abdominal aortic aneurysms in a defined population. METHODS: An epidemiologic analysis of ruptured abdominal aortic aneurysms (AAAs) was made in an urban population during a 16-year period. The study was retrospective and covered a demographically defined population of 230,000 inhabitants in the city of Malmö, Sweden. Reports of all identified ruptured AAAs in Malmö from 1971 to 1986 were analyzed. The autopsy rate in the city was 85% during this period. RESULTS: Ruptured AAAs were found in 5.6 of 100,000 persons (8.4/100,000 men and 3.0/100,000 women). No increase was found during the study period after age and sex standardization. The age-specific incidence was highest (113/100,000) in men 81 to 90 years old and (68/100,000) in women older than 90. The number of surgical interventions increased among men but not among women and the surgical mortality rate decreased from 86% to 43%. The overall mortality rate for ruptured AAA was 88%. The most common symptoms were abdominal pain and loss of consciousness. CONCLUSIONS: The validity of the study was based on a high autopsy rate. The incidence of aneurysm rupture was not low compared with other Scandinavian studies, but was low in comparison with studies from the United Kingdom. No increase in standardized rupture incidence was found. To substantially decrease the total mortality caused by rupture, operation must be performed before rupture.

Adult↗
PubMed1993

Percutaneous transluminal renal angioplasty versus surgical reconstruction of atherosclerotic renal artery stenosis: a prospective randomized study.

PURPOSE: The purpose of this prospective randomized study was to compare percutaneous transluminal renal angioplasty (PTRA) and operation as initial therapy with regard to technical results, primary and secondary patency, and effects on blood pressure and renal function in patients with atherosclerotic unilateral renal artery stenosis. METHODS: Fifty-eight patients who did not have diabetes, who were less than 70 years of age, and who had severe hypertension and significant stenosis were randomized to receive PTRA or operation. Angiography was performed 10 days, 1 year, and 2 years after treatment to verify patency, and blood pressure and renal function were simultaneously evaluated. RESULTS: Technically, PTRA was successful in 83% and operation in 97% of patients. The primary patency rate after 24 months was 75% in the PTRA group and 96% in the operative group in technically successful cases. The secondary patency rate in the PTRA group was 90% and in the surgical group 97%. To achieve these results four patients in the PTRA group required operation, and one patient in the surgical group required PTRA. Hypertension was cured or improved after additional treatment in 90% of the patients after PTRA and 86% after operation. The corresponding figures for improved or unchanged renal function were 83% and 72%, respectively. After additional treatment, effects on blood pressure and renal function did not differ. Seventeen percent of the patients treated with PTRA required surgical intervention. CONCLUSIONS: PTRA is recommended as first choice of therapy for atherosclerotic renal artery stenosis causing renovascular hypertension if combined with intensive follow-up and aggressive reintervention.

Adult↗
PubMed1993

Determination of urinary N-acetyl-beta-glucosaminidase in patients with hypertension and renal artery stenosis.

The purpose of the study was to measure the urinary excretion of N-acetyl-beta-glucosaminidase (U-NAG) in patients suspected of having renovascular hypertension and to compare the enzyme excretion before and after active intervention with operation or percutaneous transluminal renal angioplasty (PTRA). Eighty-one patients with severe, therapy-resistant hypertension were examined with regard to renal artery stenosis (RAS). At least one significant renal artery stenosis was found in 61 patients, whilst the remaining 20 patients were classified as having essential hypertension. Enzyme levels were found to be significantly higher in RAS patients as compared with patients with severe hypertension lacking significant renal artery stenosis, 0.66 (0.41-0.91, median value, 1st and 3rd quartiles) versus 0.35 (0.27-0.54); P < 0.01. Both groups of patients had significantly higher U-NAG values than a healthy reference population (0.2, 0.13-0.27; P < 0.01). Forty of the RAS patients were randomized to surgery or PTRA and followed prospectively for 2 years. After either renal vascular surgery or PTRA a significant rise in U-NAG excretion was observed 7-10 days after treatment. Urinary NAG excretion remained elevated during long-term follow-up. It is suggested that U-NAG should be determined in patients with therapy-resistant hypertension with suspicion of renal artery stenosis.

Acetylglucosaminidase↗
PubMed1993

High prevalence of diabetes in chronic leg ulcer patients: a cross-sectional population study.

In a cross-sectional survey, designed to detect all patients with current chronic leg ulcers, 27% of the patients had diabetes mellitus. The outcome for the 104 examined diabetic patients has been evaluated and compared with the 278 nondiabetic patients. The purpose was to establish the prevalence of leg ulcers among diabetic patients and to assess potential causes. The point prevalence was calculated by extrapolating the leg ulcer frequency to the total diabetic population in the studied area. The point prevalence for active leg ulcers (including foot ulcers) in diabetic patients was 3.5% (95% CI 2.8-4.2). Ulcers above the malleoli were almost as common as foot ulcers. Peripheral vascular disease was present in 67% of all ulcerated legs in patients with diabetes compared to 42% in nondiabetic patients (p < 0.001). In 72% of foot ulcers in diabetic patients arterial impairment was judged to be a contributing aetiological factor and in nondiabetic patients 45% (p < 0.001). Ulcers solely attributed to possible neuropathy were less common (15%). Ulcers with multifactorial causes were common above the malleoli. This survey has given the size of the problem and indicates macroangiopathy to be the dominating factor responsible for slow or nonhealing ulcers in diabetic patients. Objective assessment of arterial circulation is mandatory and signs of arterial impairment require consultation with a vascular surgeon.

Adolescent↗