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Biomedical subjects

N Jonsson

Publications and source records attributed to N Jonsson.

At least 55 records · Page 3Linked to original sources
PubMed1985

Tantalum markers in radiography. An assessment of tissue reactions.

The biocompatibility of two types of radiopaque tantalum markers was evaluated histologically. Reactions to pin markers (99.9% purity) and spherical markers (95.2% purity) were investigated after 3-6 weeks in rabbits and 5-48 weeks in children with abnormal growth. Both marker types were firmly attached to bone trabeculae; this was most pronounced in rabbit bone, and no adverse macroscopic reactions were observed. Microscopically, no reactions or only slight fibrosis of bone tissue were detected, while soft tissues only demonstrated a minor inflammatory reaction. Nevertheless, the need for careful preparation and execution of marker implantations is stressed, and particularly avoidance of the use of emery in sharpening of cannulae. The bioinertness of tantalum was reconfirmed as was its suitability for use as skeletal and soft tissue radiographic markers.

Animals↗
PubMed1984

Segmental hepatic arterial occlusion with absolute ethanol in domestic swine.

Four to five ml of absolute ethanol was injected into a segmental hepatic artery in eight pigs to study the occlusive effect on the hepatic arterial system. Liver cell damage was indicated by a transient moderate elevation of liver enzymes. Follow-up angiography at various time intervals showed persistent occlusion of intrahepatic arteries at different levels in all pigs and occlusion of the common hepatic artery in four. Reconstitution of the intrahepatic arterial circulation via abundant intrahepatic collaterals was, however, observed. Microscopic examinations demonstrated arterial thrombi and necroses in the vascular walls as well as a great variation in the extent of liver parenchymal damage.

Alanine Transaminase↗
PubMed1983

Partial ablation of the kidney by intraarterial ethanol in domestic swine.

Partial renal ablation was produced in 15/17 swine kidneys after segmental intraarterial injection of 1-2 ml of 95% ethanol. Complications were seen in 3 kidneys, including reflux of ethanol into nontarget vessels with subsequent total infarction of 2 kidneys, and the development of hydronephrosis in 1 kidney. Strictly selective catheterization and a very slow injection of ethanol are essential to avoid complications. This technique may find clinical application and the possible indications are discussed.

Animals↗
PubMed1982

A new method for induction of fibrous renal artery stenosis in the pig designed for the study of percutaneous balloon catheter dilatation.

An open surgical method for the creation of experimental renal artery stenosis by ligation with chromic catgut is described. Microscopic examinations at different intervals demonstrated the development of fibrosis throughout the arterial wall. These stenoses seem to provide a suitable model for the study of the effects of balloon catheter dilatation. Previously reported techniques for experimental artery stenosis induction are briefly reviewed.

Angioplasty, Balloon↗
PubMed1982

Balloon catheter dilatation of stenotic renal artery anastomoses. Experiments in the pig.

Stenotic renal artery anastomoses were produced in pigs in order to investigate the effects of transluminal angioplasty. Six weeks after surgery unilateral dilatation with a modern balloon catheter was performed in 8 pigs. These animals were reexamined with angiography and pressure gradient recording 8 to 10 weeks after dilatation and with post-mortem angiography 8 to 10 weeks later. Only 2 arteries had minimal residual stenoses, while in 6 arteries the stenoses were completely eliminated. Microscopic examination showed thinning of the fibrotic vessel wall, with defects in the internal elastic lamina.

Angioplasty, Balloon↗
PubMed1982

Experimental fibrous renal artery stenosis dilated by balloon catheter. Long-term results.

Fibrous renal artery stenosis was induced by subtotal ligation with chromic catgut. Six weeks following unilateral ligation, transluminal balloon dilatation was performed in 8 pigs. Angiography was performed 8 to 10 weeks after dilatation, and at post-mortem 20 weeks after dilatation. Intra-arterial blood pressure and renal venous renin activity were measured before and at the repeat examination after dilatation and the morphologic changes in the arterial wall were evaluated at microscopy. Restenosis developed in 2 renal arteries, while successful dilatation was achieved in 6 cases.

Angioplasty, Balloon↗
PubMed1982

Relaxation sutures for the oesophageal end-to-end anastomosis.

Intrathoracic end-to-end anastomoses were made in 4 series of piglets with 10 animals in each. In one series (S) the anastomoses were made with interrupted 6/0 silk sutures. In another series (MR) interrupted 10/0 supramid sutures were used after standardized resection. In a third series (F) 6/0 silk sutures were utilized and the oesophageal ends fastened to fascia perivertebralis with traction sutures. In a fourth series (RF) the anastomoses were made with silk 6/0 suture material after standardized resection and including traction sutures. The results were evaluated with standardized X-ray examination with calculation of anastomotic index, histological examination and macrophotography. Statistical analysis of the anastomotic index showed a significant difference between the F and S series. The anastomoses in the F series had healed with less stricture formation. No significant differences were observed between the MR and S series, the RF and S series, and the MR and RF series. Our results encourage us to recommend traction sutures in contriving an intrathoracic end-to-end oesophageal anastomosis.

Animals↗
PubMed1982

Transient lymphomatoid papulosis in mycosis fungoides.

During PUVA treatment a 66-year-old woman with mycosis fungoides in stage III suddenly developed widespread papulonodular lesions of alarming clinical and histological appearance. There was rapid spontaneous and complete regression of the eruptions, which was probably an expression of transient lymphomatoid papulosis in connection with MF.

Aged↗
PubMed1981

Transcatheter obliteration of the renal artery by ethanol injection: experimental results.

The sclerosing effect of the introduction of 95% ethanol into the renal artery was evaluated in eight rabbits and one pig. Longterm occlusion of the renal artery with ensuing infarction of the kidney could be produced by a small, easily tolerated dose. Several inherent drawbacks of currently used embolic sgents may be avoided with this technique, which is suggested for clinical trial.

Animals↗
PubMed1981

Technical considerations of experimental esophageal anastomosis.

Following transection and anastomosis of the intrathoracic esophagus, the effects of rotating the esophageal ends, lumen-widening procedures, microsurgical technique and traction sutures were studied in 8 series of 10 piglets each. The results were evaluated with contrast-medium X-ray examination and macrophotography. The different procedures were compared with single-layer end-to-end anastomosis with 6/0 silk. Anastomosis with 10/0 supramid withstood the tension in the intrathoracically stressed esophageal anastomosis, but gave no advantages. Rotating of the ends of the transected esophagus showed no significant differences. Widening the anastomotic lumen with longitudinal incisions did not result in a wider lumen. Further extension of the anastomotic circumference with a Z-shaping of the mucosa did not reduce stricture formation. Traction sutures between the esophageal wall and perivertebral fascia gave a significantly wider anastomotic lumen. There was no correlation between stricture, and the amount of granuloma, submucous leakage, or degree of histologic change.

Animals↗
PubMed1981

Dilatation of experimental renal artery stenosis by balloon catheter.

An experimental model has been developed in the pig in order to evaluate the effect of percutaneous transluminal angioplasty on fibrous renal artery stenosis. Stenoses were induced by bilateral subtotal ligation with chromic catgut. Six weeks following ligation unilateral transluminal dilatation was performed in 9 pigs using Grüntzig balloon catheters. In only one case a serious complication occurred with rupture of the renal artery. Seven pigs with dilated stenoses were re-examined by angiography 8 to 10 weeks after dilatation. In 6 cases the stenoses were practically completely eliminated while in one cases a re-stenosis developed. Microscopy of the dilated arteries revealed several small and large ruptures of th internal elastic membrane.

Angioplasty, Balloon↗
PubMed1981

Two anastomotic widening procedures for the repair of oesophageal atresia. An experimental evaluation.

Three series of piglets with 10 animals in each were operated on with intrathoracic oesophageal anastomosis. In one series the ends of the oesophagus were brought together with single 6/0 silk sutures (S). In another series with the same suture material each oesophageal end was slit (C). In a third series Z-shaped procedure of the mucosa was performed with 10/0 supramid and the muscular layers were stitched with 6/0 silk sutures (P). The results were assessed with standardized X-ray examination with calculation of anastomotic index, histological examination and macrophoto. Statistically, there was no significant difference in the anastomotic index between the C and P series compared with the control series S. The values were highest in the C series, in which there were four anastomoses that were wider than the best anastomosis in the S series. The histological examination showed in general more pronounced inflammatory and fibrotic reactions in the C and P series as compared with series S. With a great luminal difference between the two organ-ends without the occurrence of a large gap the method seems advantageous. Further widening of the anastomotic circumference with Z-shaped procedure of the mucosa was technically more demanding and did not reduce the stricture formation.

Animals↗
PubMed1979

Transcatheter arterial embolization of experimental hepatic tumours in the rat.

After transcatheter arterial embolization with Spongostan (99.3% gelatin-similar to gelfoam) in a group of rats with experimental hepatic tumours, the angiographic and microscopic findings were compared with those in a group of rats with non-embolized liver tumours. Partial recanalization of the hepatic artery was demonstrated already after 2 to 6 days. Reduced vascularization of tumours could be demonstrated after embolization and in a few animals even decrease in tumour size. Microscopy revealed a significantly greater extent of tumour necrosis in embolized tumours of large size. Necrosis of normal liver tissue was found to a varying degree in the embolized rats, while no ischemic injury was evident in livers of most non-embolized animals.

Animals↗
PubMed1977

Studies on adenovirus type 9-induced mammary fibroadenomas in rats and their malignant transformation.

After inoculating newborn W/Fu rats with adenovirus type 9, 27 of 27 females developed mammary fibroadenomas with a latency period of 14-25 weeks. No tumors were observed after inoculation with adenovirus type 5 or in males with the type 9 inoculation. After persistence of the tumors for 3-14 months, malignant transformation of the stroma resulted in different types of sarcoma in three rats: fibrosarcoma, round-cell liposarcoma, osteosarcoma and malignant mesenchymoma. In another animal the stroma of a fibroadenoma was highly cellular, suggesting a transition into fibrosarcoma. Malignant transformation of the epithelial component was not observed. Tumor cells contained adenovirus type 9-specific T-antigen, and rats with transplanted tumors were immunized to T-antigen. Mammary fibroadenomas without signs of malignant transformation developed in eight of nine female rats inoculated with adenovirus type 9 at an adult age. Neonatal thymectomy and total body x-irradiation neither significantly shortened the induction time of adenovirus 9-induced fibroadenomas nor increased the frequency of malignant transformation in females. One lipoma and one highly differentiated liposarcoma, however, appeared in two male rats. The results provide an example of the progression of a virus-induced benign tumor into a malignant neoplasm.

Adenofibroma↗
PubMed1977

Transcatheter arterial embolization of normal livers and experimental hepatic tumours in the rat.

Transcatheter hepatic arterial embolization with Spongostan (99.3% gelatin) was performed in a group of normal rats. By repeat angiography could be demonstrated that arterial occlusions lasted for at least 1 to 8 days in most rats. Microscopy of these normal livers gave no evidence of parenchymatous liver injury. At postembolization angiography in a group of rats with experimental liver tumours it could be demonstrated that arterial supply of these tumours was temporarily completely arrested. Microscopy of some of these neoplasms revealed extensive necroses. The eventual future clinical applications of this procedure as an alternative to hepatic artery ligation is discussed.

Animals↗
PubMed1977

Tumor vessels. Angiographic-histopathologic correlation.

The operative or autopsy specimens of 20 cases of renal carcinoma, 10 cases of pancreatic carcinoma and 10 cases of malignant glioma were studied histopathologically and compared with the in vivo angiographic findings. The study was focused on the presence or not of newly formed tumor vessels trying to eludicate if the abnormal vessels seen on angiography are newly formed tumor vessels or altered preexisting vessels.

Adenocarcinoma↗