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Biomedical subjects

D Bergqvist

Publications and source records attributed to D Bergqvist.

At least 415 records · Page 23Linked to original sources
PubMed1987

The effect of low molecular weight heparin on experimental thrombosis and haemostasis--the influence of production method.

Three low molecular weight heparins prepared by enzymatic depolymerization, chemical degradation, and fractionation, respectively were studied in experimental thrombosis and haemostasis models in vivo and in biological assays in vitro. The three low molecular weight heparins, which had comparable molecular weight distributions, showed very similar activities both in vitro and in vivo. All three showed dose dependent thromboprophylactic effect. The antithrombotic effects of the low molecular weight heparins and conventional heparin administered in the same dose (30 XaI u/kg b.w.) did not differ. Neither LMW heparin nor conventional heparin (60 or 90 XaI u/kg b.w.) showed significant effects on the haemostatic plug formation time in the rabbit mesenteric microcirculation. These experiments confirm that low molecular weight heparins are potential antithrombotic drugs, which by intravenous administration have effects similar to those of standard heparin. The method of preparation seems to be of no or minor importance, at least if the molecular weight distributions of the products are similar.

Animals↗
PubMed1987

Effects of an enzymatically depolymerized heparin as compared with conventional heparin in healthy volunteers.

A low molecular weight heparin (LMW-heparin) with a mean molecular weight of 4900 dalton was prepared by controlled enzymatic depolymerization of conventional porcine mucosal heparin. The effects of 2,500, 5,000 and 10,000 U (XaI; 29, 58 and 116 mg) on factor Xa inhibition (XaI), factor IIa inhibition (IIaI), APTT, AT III and platelet count were compared to those of 5,000 U (XaI; 26 mg) of conventional heparin given s.c. to 6 healthy volunteers. 5,000 U (XaI; 58 mg) of LMW-heparin was given i.v. A dose related response with regard to the XaI and the IIa-inhibitory activities with peak values at 4 hours after the s.c. injections was obtained. An increase of the XaI/IIaI ratio over the time after injection was seen only after i.v. administration of the LMW-heparin. The APTT was only slightly prolonged and remained within normal range after s.c. injection. AT III and platelet counts were unaffected. The biological half life of the LMW-heparin was 111 minutes if assayed by Xa inhibition, 76 minutes if assayed by IIa inhibition and 40 minutes if assayed by APTT. A strong correlation between the XaI activities obtained and body weight was seen, indicating that LMW-heparin should be administered individually according to body weight.

Adult↗
PubMed1987

Late ischaemic sequelae after umbilical artery catheterization.

The acute complications of umbilical artery catheterization are well recognized but very little is known about long-term consequences. Two cases are presented which indicate that umbilical artery catheterization during the neonatal period may give rise to late ischaemic complications.

Arterial Occlusive Diseases↗
PubMed1987

Prostacyclin and thromboxane release from the vessel wall--comparison between an incubation and a perfusion model.

Prostacyclin (measured as its stable degradation product 6-keto-PGF1 alpha) and thromboxane (measured as its stable degradation product TxB2) produced by the vascular wall were measured by radioimmunoassay (RIA). Four pieces from the rabbit aorta and four from the caval vein were used. One piece was incubated in Hank's balanced salt solution (HBSS), one piece with additional indomethacin, and the other pieces were mounted in a perfusion system so that only the endothelium was exposed to the buffer solution with or without indomethacin. There was a higher release in the piece incubated in the buffer than in the piece which was perfused, indicating that not only the endothelium releases prostacyclin and thromboxane from the vascular wall. The 6-keto-PGF1 alpha/TxB2 ratio was higher in the perfused than in the incubated samples suggesting that 6-keto-PGF1 alpha release is higher in the endothelium than in the other wall layers and/or that TxB2 production is higher in the outer layers than in the inner layers. No correlation was found between the release from the incubated vessel and from the perfused vessel. There was a higher release of 6-keto-PGF1 alpha from aortas than from caval veins, when incubated or perfused, whereas there was a tendency to a higher release of TxB2 from veins than aortas.

6-Ketoprostaglandin F1 alpha↗
PubMed1987

Analysis of complications after percutaneous transluminal angioplasty of renal artery stenoses.

During a five-year-period percutaneous transluminal renal angioplasty (PTRA) was attempted in 90 renal arteries with 109 stenoses and 3 occlusions in 78 patients. Complications were systematically recorded and classified as major, minor and radiological-technical. Twenty-one major complications (20.8%) including one fatality occurred as well as 17 minor, (16.8%) and 37 radiological-technical (36.6%) problems. The last group showed no clinical symptoms. The frequency of complications in our series is high compared with that in a survey of ten papers reviewing results in 675 patients. The most marked discrepancy was our high frequency of septic problems. Radiological changes are not usually reported in other series, probably because they are regarded as methodological but we considered these as potentially dangerous and important to report as they can lead to clinically relevant complications. Because of the problems reported here PTRA should only be performed in centres where complications can be properly dealt with.

Acute Kidney Injury↗
PubMed1987

Secondary aortoenteric fistulas--an analysis of 42 cases.

Secondary aortoenteric fistulas are seen with an increasing frequency which parallels the expansion of reconstructive vascular surgery. During a 12-year period 42 cases have been collected from the hospitals, which perform most of the vascular surgery in Sweden (0.7% of vascular operations). Twenty-five were seen after operation for aortic aneurysm, 15 for aortoiliac occlusive disease, one after renal artery ligation (as a part of reconstruction for renovascular hypertension) and one after operation for an iliac pseudoaneurysm. The frequency of complications during and after the primary operation was high. The interval between operation and onset of fistula symptoms was significantly shorter if there had been infectious complications, the median interval was 32 months, the longest being 10 years. The most important symptom was gastrointestinal haemorrhage, consisting of several small bleeds often combined with septic complications. A large number of negative investigations usually preceded the final diagnosis which was made at exploratory laparotomy. After surgery for the fistula the frequency of complications and mortality, were very high. Mortality was 58%, the most common cause of death being a blow out of the aortic stump. Of those leaving hospital, several further operations were performed with a high mortality. Recurrence of the fistula occurred in 16 out of 34 patients who survived surgery. At follow-up (12-74 months after fistula closure) seven patients were still alive.

Adolescent↗
PubMed1987

Management of early neurologic deficits after carotid thrombendarterectomy.

A neurologic deficit appearing during the early postoperative period after an interval following an otherwise successful carotid endarterectomy may be caused by thrombotic material formed in the carotid bifurcation. Our experience of immediate reoperation on eight such cases during a period of 2 years is reported in this paper. Thrombotic occlusion was found at reoperation in seven cases and a non-occluding thrombus in one case. Four of the patients were fully restored immediately after reoperation. In two cases good recovery but with some persisting symptoms was seen. One patient became hemiparetic with moderate restitution and one suffered a dense hemiplegia. We recommend an aggressive approach with immediate reoperation in these cases.

Aged↗
PubMed1987

Hemorrhagic complications resulting in reoperation after peripheral vascular surgery: a fourteen-year experience.

Eighty-nine patients who underwent reoperation because of hemorrhagic complications after peripheral arterial surgery were studied and compared with 103 patients without such complications. Elevation of erythrocyte sedimentation rate, serum creatinine values, and blood pressure before anesthesia was found more often in patients with hemorrhage. The frequency of reoperation due to control hemorrhage was 2.8%; femorodistal and carotid reconstructions were complicated by hemorrhage requiring reoperation significantly more often than other types of vascular surgery, 3.2% and 4.2%, respectively. The use of vacuum drains apparently did not contribute to the diagnosis of bleeding requiring reoperation. Amputation was a more frequent outcome in femorodistal reconstructions complicated by hemorrhage than in similar operations without this complication. After reoperations performed within 48 hours of the primary operation, the clinical course mostly was uncomplicated, whereas in reoperations performed later the bleeding usually was associated with infection of the reconstruction, resulting in a higher frequency of amputation. Most of the late hemorrhages occurred in groin incisions.

Amputation, Surgical↗
PubMed1987

Postoperative deep venous thrombosis after renal transplantation. Effects of cyclosporine.

In this prospective study the frequency of deep venous thrombosis during the first three weeks after renal transplantation was determined using a combination of strain gauge plethysmography and thermography for objective diagnosis. Ninety-seven consecutive patients were studied, 30 patients having juvenile diabetes mellitus. As immunosuppression cyclosporine and low-dose steroids were used. The series was compared with a similar group of 83 patients, 33 having juvenile diabetes mellitus treated with azathioprine and high-dose steroids as immunosuppression, in which the diagnosis of deep venous thrombosis was made with an identical technique. The overall frequency of thrombosis was 9.3% in the cyclosporine-treated group, which is a significant reduction in comparison with the azathioprine group (24.1%). It is concluded that the combination of cyclosporine and low-dose steroids does not increase the frequency of deep venous thrombosis in comparison with azathioprine and high-dose steroids in renal transplanted patients.

Adolescent↗
PubMed1987

Terbutaline and budesonide as inhibitors of postischaemic permeability increase.

A temporary ischaemia with total circulatory arrest of the hamster cheek pouch was obtained by clamping the neck of the everted cheek pouch. The macromolecular permeability increase in postcapillary venules was quantified as the leakage of fluorescein-labelled dextran using intravital microscopy and a fluorometer simultaneously. At reperfusion after 30 min ischaemia, there was a significant and reversible permeability increase. This response could be totally prevented by topical administration of either terbutaline, a selective beta 2-receptor agonist, or budesonide, a glucocorticoid, but it was not significantly impeded by the antihistamine mepyramine. The study shows that, in conformity with the situation in inflammation, the postischaemic permeability increase at reperfusion after ischaemia can be blocked by either beta 2-stimulation or glucocorticoids. Furthermore, it indicates that histamine, a common inflammatory mediator, is not responsible for the postischaemic permeability increase.

Animals↗
PubMed1987

Acute thrombogenicity of a compliant polyurethane urea graft compared with polytetrafluoroethylene: an experimental study in sheep.

The acute thrombogenicity of a new polyurethane urea graft has been compared with polytetrafluoroethylene (PTFE) grafts using labelled homologous platelets in the carotid arteries of sheep in a low-flow model. There was no difference in patency. Thrombus weight and thrombus free surface were the same in both types of graft after 4 h. The accumulation of homologous 32P platelets was measured at the 2 anastomoses and at a midgraft position. At no point was there any statistically significant difference between the 2 grafts, but the activity was always somewhat higher in the polyurethane grafts. Although more compliant, in this study polyurethane urea grafts behaved much like PTFE ones.

Animals↗
PubMed1987

Effects of different graft preparation techniques on the acute thrombogenicity of autologous vein grafts. An experimental study in sheep.

The effects of different techniques of preparing autologous vein grafts on acute thrombogenicity have been studied in a sheep model. Storing grafts at room temperature or rinsing with different solutions seemed to be of minor importance, whereas distending them to a pressure of 400 mm Hg significantly reduced patency and increased platelet accumulation and thrombus formation.

Animals↗
PubMed1987

Vascular injuries during gynecologic surgery.

Iatrogenic vascular injuries are common in the civilian western world. The frequency seen following gynecologic surgery is not known and a questionnaire was therefore sent to all gynecologic clinics in Sweden undertaking surgery, to establish the frequency during a 5-year period and to analyse the types of injury. Case reports in the literature were also analysed. The frequencies per 10,000 operations were: after laparoscopy, 0.93, after laparotomy, 0.76 and after major vaginal surgery, 0.33. All laparoscopic injuries were localized to the iliac arteries, caused bleeding, and were treated with arterial suture without complications or late sequelae. Injuries during laparotomy were most frequently venous and all patients had hemorrhage as the main symptom. In one case the external iliac vein was ligated, with immediate postoperative swelling, and in another case the external iliac artery was ligated, after which the patient developed postoperative ischemia. The internal iliac veins were ligated, and the other vessels reconstructed. There was no mortality, but a high rate of morbidity, also with late sequelae.

Adult↗