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Biomedical subjects

T M Scheinin

Publications and source records attributed to T M Scheinin.

At least 55 records · Page 3Linked to original sources
PubMed1981

Haemodynamic changes after portal vein ligation and mesocaval interposition "H" grafting in the dog.

The haemodynamic effects of portal ligation combined with mesocaval H-grafting were evaluated experimentally as follows: acute portal hypertension was induced in 20 mongrel dogs by ligation of the portal vein, in 15 of these a mesocaval shunt was constructed using an autogenous venous segment, the rest served as controls and were left without shunting. All animals with portal occlusion only died within 80 minutes, whereas nine dogs in the H-graft groups survived. The one-month patency rate was 78 per cent. Slight portal hypertension was observed only in the early post-shunt period, one month later the pressure was normal. By this time the flow through the shunt was significantly reduced and numerous but small portosystemic collaterals were visualized radiographically. Varices formation was not observed. The Xe-133 wash-out of the liver and liver pO2 were normal in the early post-shunt period. These findings were in marked contrast to those in the control group where both variables showed rapid deterioration. The pre-shunt spleen flow proved to be of prognostic significance: poor flow was associated with bad prognosis. After one month the liver flow was decreased whereas the spleen flow was increased, perhaps indicating increased splenocollateral flow. Portal ligation combined with mesocaval H-grafting thus seemed to induce slight and temporary portal hypertension in this model. This appeared to be caused by relatively narrow lumen of the shunt. Normotension was soon established by rapid opening up of portosystemic collaterals.

Animals↗
PubMed1981

Fiberendoscopic cannulation of the papilla of Vater I. Sphincterotomy in the treatment of retained bile duct stones and benign papillary stenosis.

Endoscopic sphincterotomy (EST) has been used as a treatment of 33 patients with bile duct stones and 3 patients with benign papillary stenosis. In 83% the papilla was cannulated and an adequate, 15 mm long, sphincterotomy was performed. In 72% the retained bile duct stones were extracted. All 3 patients with papillary stenosis had a free bile flow to the duodenum after the procedure and no complications were seen. Complications occurred in 4 patients (11%) with bile duct stones. The complications consisted of pancreatitis in 2 patients, bleeding in one patient and cholangitis in one patient. One of these patients died 5 days after the procedure because of extraperitoneal perforation of the duodenum accompanied by haemorrhagic pancreatitis. Although many of the patients were old and in poor condition endoscopic sphincterotomy was well tolerated when the procedure was uneventful. The method was usually painless and general anaesthesia was not required. The hospital stay after EST was 6.6 +/- 1 days on average.

Aged↗
PubMed1980

Rhabdomyosarcoma of the oesophagus. Light and electron microscopic study of a rare tumor.

A 61-year-old man was operated for a large tumor, 12 x 4 cm in size, in the lower third of the oesophagus. The tumor had the appearance of a pleomorphic rhabdomyosarcoma showing cross striations by light microscopy and typical sarcomeres by electron microscopy. This is the fifth undisputed oesophageal rhabdomyosarcoma described in the literature and the first examined using electron microscope.

Esophageal Neoplasms↗
PubMed1980

Connective tissue changes in syngeneic aortal vein grafts in rats.

The supradiaphragmatic inferior vena cava was syngeneically transplanted into the infrarenal part of the abdominal aorta in rats of inbred strains. The initial histologic changes coincided with the changes usually seen in wound healing during the inflammatory phase and the phase of fibroplasia. Later the reparative process occurred predominantly in the luminal part of the vein wall, and was usually seen as intimal hyperplasia. In some grafts this process caused a narrowing of the lumen. In this particular experimental model the thickening of the intimal layer was mainly due to organization of fibrin layering thrombus. This was shown by detection of lamellar fibrin deposits and a high concentration of fibronectin in this layer. A large amount of fibronectin was detected in and around the proliferating fibroblasts and in thrombi. This explains the high concentration of fibronectin in the proliferating intimal layer of the graft.

Animals↗
PubMed1980

Collagen metabolism in syngeneic aortal vein grafts in the rat.

The sequential changes in hydroxyproline concentration and in vivo 3H-proline incorporation in arterialized grafts of the supradiaphragmatic inferior vena cava have been studied. These grafts were transplanted from one rat to the abdominal aorta of another rat of the same inbred strain, i.e., syngeneic grafts. The hydroxyproline (collagen) concentration decreased to half of its pregraft value one week after the transplantation and thereafter increased again, reaching its peak value 4 weeks after transplantation. The pregraft level of collagen concentration was not reached within the observation period of 12 weeks., The incorporation of 3H-proline increased and reached its peak value one week after transplantation. The values then levelled off and one month after the transplantation were slightly elevated. These results indicate that the reduction of collagen concentration after grafting was due to an increased breakdown, which was compensated by increased collagen synthesis. This probably signifies that the collagen in the vein wall is remodelled as a response to the altered hemodynamic milieu following its insertion to the arterial circulation. The collagen concentration did not reach pregraft level. This is most likely due to a relative increase of ground substance, smooth muscle cells and elastin in the vein wall.

Animals↗
PubMed1979

Liver damage after liver hilus dearterialization in dogs.

Twenty-one harrier dogs underwent a standardized liver hilus dearterialization with (7) or without (14) cholecystectomy using six sham-operated dogs as controls. Seven dogs died, only one of which was in the dearterialization and cholecystectomy group. S-OCT and s-GDH were increased at 90 minutes after dearterialization. There was no statistical difference between the groups at 90 minutes. On the first day after dearterialization, the activity of s-OCT, s-GDH, s-ALAT rose significantly (p less than 0.005). The activity of s-ASAT was, however, increased to the same extent both in the dearterialized and the sham-operated animals. A normalization of the serum enzyme activities was usually seen after one week. S-ALP increased on the first day (p less than 0.005) and still higher values were noted on the seventh day after dearterialization. Cholecystectomy did not affect any of these results except mortality. Liver oxygen consumption, in vitro was unchanged throughout the experiment. The oxygen consumption of bile duct mucosal scrapings one week after dearterialization was similar to the corresponding values in the controls. The results indicate that the dearterialization leads to a definite but mild and reversible mitochondrial and cell membrane damage. The results indicate further the need of adequate controls when the effects of dearterialization on the liver are studied.

Alanine Transaminase↗
PubMed1978

Liver blood flow after liver hilus dearterialization.

Changes in liver blood flow immediately after and during one week after a standardized liver hilus dearterialization were studied in a series of 16 dogs. An additional six dogs were sham-operated and used as controls. The liver blood flow was measured using Xe133 injections administered by two methods in every animal: into the liver parenchyma, and into the portal vein. The measurements were taken immediately before, and 15, 30, 60 minutes, and one and seven days after the operation. Xe133 wash out from the liver was found to be reduced 15 minutes after the dearterialization, measured both by liver parenchymal and portal venous injection routes (p less than 0.05). Return to normal took place rapidly thereafter. On the next day some increase in the liver blood flow was observed in both dearterialized and sham-operated dogs. The aleration was significant in the dearterialized animals as measured by portal vein injections, and in the sham-operated dogs as measured by liver parenchymal injections (p less than 0.05). On the seventh day normal Xe133 liver wash out was recorded in all animals. It can be concluded that after liver hilus dearterialization in the dog liver blood flow was decreased for a very short period of time only. Increased flow was noted as early as the next day, not only in the dearterialized, but also in the sham-operated animals. The use of adequate controls is important.

Animals↗
PubMed1978

Transient liver hypoxia after liver hilus dearterialization.

Dearterializaton of the liver causes changes which have been thought to be ischaemic in nature. Previous reports of direct measurements of liver tissue gas tensions have been confined only to the acute postoperative phase. In this study 15 dogs underwent a standardized and angiographically controlled liver hilus dearterialization with (6 dogs) or without (9 dogs) cholecystectomy. Six dogs underwent a sham operation and were used as controls. Liver respiratory gas tensions were measured with a Silastic tonometer intraoperatively during the first 90 minutes after dearterialization and on the first and seventh day postoperatively. Six dogs died, only one of these being in the dearterialization and cholecystectomy group. Liver pO2 decreased from the mean of 33.2 mmHg to a level of 15--20 mmHg in 20 minutes (p less than 0.05) during room air breathing. On the next day the liver pO2 values were normal. There was no difference in pO2-Values between the cholecystectomy and the noncholecystectomy groups. Liver pCO2 increased from the mean of 26.4 mmHg to 55--60 mmHg in the same time (p less than 0.05). However, on the first postoperative day normal values were seen only in the cholecystectomy group. 60% oxygen breathing prevented the changes in both liver pO2 and pCO2. No changes were noted in the liver gas tensions of the sham-operated dogs, not in the systemic arterial pO2 and pCO2 of the dearterialized animals. Thus a transient hypoxic state developed after this operation, which lasted for less than one day. This hypoxia may be prevented by 60% oxygen breathing postoperatively.

Animals↗
PubMed1975

Femoropopliteal and femorotibial arterial reconstructive surgery. Special reference to the autogenous venous bypass procedure using unreversed vein after eversion valvectomy.

The outcome of 127 femoropopliteal and 23 femorotibial arterial reconstructions carried out between January 1960 and December 1972 has been reviewed. The operative method was autogenous saphenous vein bypass in 109 cases, 82 of which were performed using unreversed vein with eversion valvectomy. The indication for reconstruction was advanced ischemia in 39%. Two patients died primarily and 23 late deaths have occurred subsequently. 19 grafts or reconstructed segments became occluded primarily. Most of them were femorotibial reconstructions of Dacron bypass reconstructions. Most of the failures occurred within 1 year of surgery. Using eversion valvectomy technique, the 1- and 5-year patency rates were 57 and 50% respectively. In femorotibial reconstructions the 1-year patency rate was 36%. There was a distinct difference in patency between the cases with excellent of good outflow and those with fiar or poor outflow. The difference was less distinct between patients with claudication and those with advanced ischemia. Eight limbs needed major amputation.

Adult↗