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Biomedical subjects

B Risberg

Publications and source records attributed to B Risberg.

282 records · Page 16Linked to original sources
PubMedDate not supplied

Options for treatment of persistent aneurysm perfusion after endovascular repair.

Persistent aneurysm perfusion represents failure of endovascular repair. The leak may occur around either end of the prosthesis or through a collateral route. Most cases can be treated by endovascular means. Stents can be rotated, the prosthesis can be lengthened at either end, and collateral pathways can be occluded, all without recourse to open repair. This report describes the management of persistent aneurysm perfusion in five patients from a total experience of 32 cases of endovascular aneurysm repair.

Aneurysm↗
PubMedDate not supplied

Treatment of descending thoracic aneurysms by endovascular stent grafting.

PURPOSE: Endovascular stent-graft treatment for true aneurysms of the descending thoracic aorta is a valid and effective alternative to conventional surgery. A review of our experience with 21 consecutive patients is reported and technical considerations are discussed. METHODS: Twenty-one patients (mean age 73 years) with true aneurysms of the descending thoracic aorta (n = 14) or contained rupture (n = 7) were treated between October 1999 and July 2001. Seven patients (33%) underwent emergency endovascular procedure. Postoperatively, the patients were followed with CT scans at 1, 3, 6, and 12 months. Follow-up, which averaged 17 months, was 100% complete. THIRTY-DAY RESULTS: No conversions to open repair were necessary. Two patients died (10%), one of acute intestinal ischemia and the other because of multiorgan failure. Four patients showed endoleaks immediately after stenting. Two patients required new endovascular stentgrafts, while the remaining two were treated conservatively. Besides endoleaks, eight major complications occurred in six patients (two stroke, two paraplegia, two respiratory insufficiency, and one renal failure). MID-TERM RESULTS: Three more patients died during the follow-up period. One patient died of heart failure after a complicated postoperative course, 91 days after stenting. The second patient died because of aortic rupture, 139 days after stenting. The third patient died of heart failure, 15 months after the endovascular procedure. The remaining 16 patients are alive and have been regularly controlled by CT scans. No late migration or endoleaks have been detected. In all the survivors, the size of the aneurysm was unchanged or diminished. CONCLUSIONS: Treatment of descending thoracic aortic aneurysms by endovascular stentgraft devices has good early and mid-term results. More accurate selection of patients may further reduce mortality and morbidity.

Aged↗
PubMedDate not supplied

Urokinase plasminogen activator colocalizes with CD25+ cells in atherosclerotic vessels.

Proteolytic activity in vascular tissue is necessary for cellular migration, remodelling of extracellular matrix and the development of atherosclerotic lesions. Inflammatory cells, mainly macrophages, are numerous in atherosclerotic plaques and may synthesize and secrete proteolytic enzymes. The principal activator of plasminogen in tissues is urokinase plasminogen activator (u-PA). To determine if an activated phenotype of inflammatory cells colocalizes with local expression of u-PA in atherosclerotic vessels, vascular biopsies from 15 patients with peripheral atherosclerotic disease were analyzed by immunohistochemistry on consecutive sections. Anti-CD68 antibodies were used as markers for macrophages and were positive in 14/15 specimens. Anti-CD25 (interleukin-2 receptor-alpha) antibodies were used to identify inflammatory cells with an activated phenotype and were positive in 9/14 CD68+ specimens. The same 9 specimens were positive for u-PA. A positive reaction for u-PA was found only in specimens with CD25+ cells. Specimens with positive reactions for all three antibodies were further analyzed with computer-assisted image analysis. The colocalization with u-PA was higher for CD25 compared to CD68 in all specimens. Mean percentage of the u-PA-positive area in regions positive for cellular markers was 52% (SEM 6%) for CD25 and 19% (SEM 5%) for CD68 (p < 0.01). The results indicated that the activation of macrophages in atherosclerotic vessels may modulate local proteolysis and be of importance in plaque development and stability.

Aged↗
PubMedDate not supplied

N-Glycans influence the in vitro adhesive and invasive behaviour of three metastatic cell lines.

Alterations in cellular glycosylation may play a key role in metastatic behaviour of tumour cells. We studied three metastatic cell lines, LOX (malignant melanoma), FEMX (malignant melanoma) and MA-11 (mammary carcinoma). These cell lines have a very different metastatic behaviour in vivo, and different glycans have been postulated to be partly responsible for these differences. To further investigate the functional role of carbohydrates, these three cell lines have been treated with tunicamycin, an inhibitor of the biosynthesis of N-glycans and benzyl- alpha-N-acetylgalactosamine (benzyl-alpha-GalNAc; BnGalNAc), an inhibitor of mature O-linked glycans. Various in vitro adhesion and invasion assays were undertaken for functional studies. Tunicamycin significantly inhibited adhesion to laminin, but only slightly affected cell adhesion to collagen IV. The same compound significantly decreased cellular invasiveness through a Matrigel invasion chamber. Moreover, tunicamycin reduced homotypic aggregation of cells. BnGalNAc had generally little effect on cell behaviour in in vitro assay. The effects of the inhibitors were, however, to some extent cell line-specific. We conclude that N-glycans, but probably not mature O-glycans have important in vitro functions in cell adhesion to laminin, cell invasion through Matrigel and cellular aggregation in the studied cell lines. These results support the view that carbohydrates are functionally involved in several steps of the metastatic process.

Acetylgalactosamine↗
PubMedDate not supplied

Lung thermal volume as an indicator of pulmonary extravascular water.

Double-indicator dilution methods can be used for measurement of lung water. The thermal conductivity method is based on heat as a diffusible and conductivity as a non-diffusible indicator. In the present study we correlated lung thermal volume with gravimetrical measurement of extravascular lung water after thrombin-induced microembolization in dog lungs. The embolization was accompanied by significantly increased vascular permeability and accumulation of interstitial water. Under these conditions there was a close correlation between the two methods of measuring lung water (r = 0.78, p less than 0.01).

Animals↗
PubMedDate not supplied

Use of formalin fixed, paraffin embedded tumours for estimation of cellular DNA content and S-phase fraction by static cytofluorometry.

Sections with a thickness of 50 micron from 34 formalin fixed, and paraffin embedded tumours were deparaffinized and hydrated and the cells were disaggregated with pepsin. The cells were stained with Hoechst 33258 and a rapid method for static fluorometry was used. DNA ploidy and the fraction of cells in S-phase were estimated and compared with results obtained with freshly prepared cells. The coefficients of variation for the tumour stemlines for both the fresh and the embedded material were approximately 6 per cent. There was a good correlation between DNA ploidy determined from fresh and embedded material, respectively; there was also a close correlation between the fractions of S-phase cells estimated from fresh and embedded tumours. It was also possible to cut out small histologically defined lesions, such as carcinoma in situ of the breast from thick paraffin sections and obtain DNA histograms with high resolution.

Bisbenzimidazole↗
PubMedDate not supplied

Sleeve anastomosis of the intestine. Physical and biochemical studies of a new intestinal anastomosis in rats.

A new, sleeve-shaped interpositional anastomosis of the small intestine was tested in rats. It was compared with a conventional two-layer anastomosis as regards healing, bursting strength, collagen content and complications. Each type of anastomosis was constructed in a separate group of 38 rats. The complications rate did not differ between the two groups. At 2 and 4 days postoperatively the bursting pressure was significantly higher in the sleeve anastomosis than in the conventional anastomosis. Hydroxyproline content did not differ between the two types of anastomosis. The study demonstrated superior breaking strength of sleeve anastomosis in the early postoperative period compared with conventional two-layer anastomosis. This finding merits further investigation.

Anastomosis, Surgical↗
PubMedDate not supplied

Endothelial fibrinolysis and ultrastructure following graded mechanical trauma.

For study of the progression and resolution of endothelial damage following mechanical vascular trauma in rats, the effects of a clamp with hydrostatically controlled occlusion pressure were compared with those of a standard mechanical clamp. The endothelial morphology was investigated with scanning electron microscopy and its function with histochemical analysis of plasminogen activator activity. Arterial or venous compression with hydrostatic pressure 1.5 kPa (11 mmHg) for 5 or 20 min produced de-endothelialized areas in veins, but only slight endothelial elevation in arteries. Hydrostatic occlusion of arteries with 12 kPa (90 mmHg) for 30 sec did not affect endothelial morphology and fibrinolytic activity, but after occlusion for 5 or 20 min the endothelium in both arteries and veins was severely damaged. The effects of hydrostatic (12 kPa) clamping on endothelial morphology and function after 5 or 20 min did not differ from those of mechanical (48 kPa = 360 mmHg) clamping. Apposition of vascular walls, except for the shortest time (30 sec) thus injured the endothelium, but minimizing occlusion pressure may reduce structural damage in the vessel wall.

Animals↗