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Biomedical subjects

S Bengmark

Publications and source records attributed to S Bengmark.

At least 145 records · Page 8Linked to original sources
PubMed1989

Islet transplantation to the renal subcapsular space in streptozotocin-diabetic rats: short-term effects on glucose-stimulated insulin secretion.

The immediate and short-term effects of transplantation of freshly isolated islets on glucose-stimulated insulin secretion were studied in streptozotocin-diabetic rats. At 2 days after the intravenous injection of streptozotocin (70 mg/kg), either 400 or 1000 freshly isolated, hand-picked islets were transplanted to the left renal subcapsular space. Intravenous glucose infusion (10 mg/min) performed 1, 3, 6, and 10 days after transplantation revealed that already at day 3, rats transplanted with 1000 islets had a significant plasma insulin response to glucose, though the response was lower than in healthy controls. At 6 and 10 days after transplantation, the 1000 islet-transplanted group of rats had a near-normal plasma insulin response to glucose. Basal plasma glucose levels were, however, still slightly elevated. Rats transplanted with 400 islets had a significant plasma insulin response at 10 days after transplantation, though the response was lower than in those transplanted with 1000 islets. It is concluded that a near-normal in vivo insulin secretory response to glucose is already obtained 6 days after transplantation with 1000 freshly isolated islets to the left renal subcapsular space in streptozotocin-diabetic rats. However, a slight hyperglycemia persists.

Animals↗
PubMed1989

Alcohol sclerotherapy of non-parasitic cysts of the liver.

Between 1980 and 1987, nine patients with non-parasitic cysts of the liver were treated with computed tomography-guided percutaneous puncture and evacuation of the cyst contents followed by injection of absolute alcohol as a sclerosing agent. During the same period only one patient was treated with surgery. The patients included seven women and two men with a mean age of 62 years. Three patients had a single cyst and six patients had multiple cysts. The size of the largest cysts varied between 5 and 20 cm (mean 10 cm). Patients with multiple liver cysts had repeated punctures and sclerosing procedures (up to eight times); 50-3100 ml of cyst fluid (mean 650 ml) was drained per procedure. One patient had symptoms of moderate alcohol intoxication; otherwise no complications were noted. Follow-up was performed with computed tomography or ultrasonography for 8-54 months (median 18 months). The results have been considered successful in eight out of nine patients who had cyst regression and reduced symptoms. Two patients, however, required additional surgical treatment due to residual and multiple cysts. Computed tomography-guided alcohol sclerotherapy of non-parasitic liver cysts appears to be a safe and effective initial therapy.

Adult↗
PubMed1989

Management of pancreatic pseudocysts.

Between 1969 and 1987, 68 patients with pancreatic pseudocysts were treated. The median cyst size was 10 cm (range 2-25 cm). Nine patients were managed conservatively with resolution of the pseudocyst occurring in eight patients. These patients had significantly smaller (median 4 cm) cysts compared with those in both percutaneously and surgically treated patients (P less than 0.01). In 22 patients the pseudocysts (median 9 cm) were punctured percutaneously under ultrasound guidance and the cyst fluid was aspirated or drained through a catheter. Complete resolution occurred in 13 patients after 1-4 (mean 1.8) punctures per patient, regression occurred in six patients after 1-4 (mean 2.0) puncture procedures per patient and three were unchanged. No complications were noted, except that two patients treated percutaneously required additional surgery. Thirty-seven patients were managed surgically (median cyst size 11 cm) with external drainage (12 patients), cystgastrostomy (17 patients), cystduodenostomy (three patients) cystjejunostomy (three patients) and pancreatic resection (two patients). Resolution of the cyst was noted in 29 patients, regression in five and three were unchanged. Five patients required additional surgery. Twelve complications were seen in ten patients (27 per cent), most frequently after external drainage. One patient died after surgical treatment. Mean hospital stay was 13 days among patients treated conservatively and 30 days in both percutaneously and surgically treated patients. Aspiration or catheter drainage of pseudocyst fluid guided by ultrasonography seems a safe and effective treatment of pancreatic pseudocysts and should be considered as initial therapy. If surgery is required cystgastrostomy is preferred.

Adult↗
PubMed1989

Insulin response to glucose challenge after transient hepatic dearterialization for rat liver malignancy.

In the palliative treatment of liver malignancy, hepatic dearterialization is being increasingly used. To study the metabolic consequences of this treatment, the present investigation was conducted to elucidate the insulin, glucose, and lactate responses to an intravenous glucose challenge after transient hepatic dearterialization in a liver tumor model in inbred Wistar-Furth rats. We found that nonfasted rats bearing dearterialized liver tumors showed slightly higher basal plasma glucose levels and an exaggerated elevation of plasma glucose during the glucose infusion compared to the controls. Further, they had a depressed insulin response to the glucose challenge. Their glycogen stores were at the same time depleted, in both the liver and the tumor tissues, and the plasma lactate production during the glucose infusion was elevated after dearterialization. We conclude that immediately after hepatic dearterialization in rats with liver malignancies, glucose intolerance and impaired glucose-induced insulin secretion exist.

Adenocarcinoma↗
PubMed1989

Glucose turnover in rats undergoing transient dearterialization for liver malignancy.

With the development of new techniques for hepatic dearterialization, their use in the treatment of liver malignancies has increased. It is therefore important to study the metabolic consequences of hepatic dearterialization. The present investigation determined the glucose turnover during hepatic dearterialization in the rat with the use of a primed tracer [( 3-3H]glucose) infusion technique. It was found that the glucose elimination rate was diminished during dearterialization in both tumor-free and tumor-bearing rats in the fasting state. Hepatic glucose production was maintained in tumor-free rats leading to hyperglycemia, but hepatic glucose production decreased in tumor-bearing rats resulting in hypoglycemia. Pretreatment of tumor-bearing rats overnight with an intravenous glucose infusion did not counteract the reduced hepatic glucose production during dearterialization in tumor-bearing rats. The hypoglycemic tendency therefore remained. This could be caused by the exaggerated glucose consumption that is known to occur in tumor tissues. It is concluded that hepatic dearterialization reduces glucose elimination in rats, and, in tumor-bearing rats, the procedure also reduces hepatic glucose production.

Animals↗
PubMed1989

Retarding liver cancer growth in the rat by transient repeated hepatic dearterialization.

The effect of repeated ischemic episodes to experimental liver tumors is studied in a group of inbred Wistar-Furth rats. A vascular occluder model was developed specially for the purpose of delivering intermittent compressions to the hepatic artery in the rat. With five daily 1-hr occlusions of the hepatic artery, rats benefited from significantly reduced tumor growth rates compared with controls that underwent sham operation (P less than 0.05). In contrast to results from previous pig experiments, it is demonstrated by angiographic studies that repeated transient dearterialization does not entirely overcome the problem of collateral vessel formation in the rat. Tumor neovascularization continues irrespective of whether the tumor is being dearterialized. It is also observed that in both normal and tumor rats, collateral channels from the left gastric artery temporarily open up when the hepatic artery is obstructed but disappear on reestablishment of flow. As such types of collateral flow are beyond our control, it is imperative that future developments in vascular occlusion therapy should aim at shortening ischemia time and combining with chemotherapy.

Adenocarcinoma↗
PubMed1989

Status of ischemic therapy for hepatic tumors.

The use of hepatic artery ligation or permanent dearterialization as the sole procedure for the palliation of patients with malignant hepatic tumors has no proved value. The combination with cytotoxic drug administration via the portal route may offer some advantage. The use of transient dearterialization with one longer ischemic period has been successful in the treatment of metastatic carcinoid disease with carcinoid syndrome but ineffective in the treatment of other hepatic tumors. New knowledge of the effects of transient ischemia on the formation of arterial collaterals and the pathophysiologic mechanisms in cellular injury has led us to further refinement of this therapeutic principle. The first results of repeated short periods of ischemia are promising and give some hope for the future palliation of this group of tumor patients.

Combined Modality Therapy↗
PubMed1989

Diagnostic cholangioscopy--comparison with conventional methods (radiology, ultrasonography).

The goals of surgery for calculous biliary disease are to explore as few normal bile ducts as possible and to remove all calculi. The most commonly used techniques to help eliminate residual stones are: exploration of all or most common ducts; operative cholangiography; intraoperative ultrasonography or choledochoscopy. Exploration of common bile ducts on clinical diagnoses leads to high number of negative explorations and has been abandoned. Operative cholangiography performed with modern technique with the use of fluoroscopy is very accurate with a diagnostic accuracy of well above 95%. Cholangiography can be performed preoperatively with the same diagnostic accuracy and thereby save operative time. Intraoperative ultrasonography has recently been introduced for the diagnosis of residual stones and seems to be superior to cholangiography. It is of limited use however, for intrahepatic stones. Intraoperative choledochoscopy finally is the most superior way of achieving intraoperative diagnosis of common bile duct stones. With the advances of ERC and other non-operative techniques, the consequences of leaving calculi in the bile duct are less severe today than before. Non-operative retrieval by percutaneous, endoscopic means or chemical dissolution are effective ways of dealing with residual stones.

Bile Duct Diseases↗
PubMed1989

Improvement of liver preservation quality with UW solution by chlorpromazine pretreatment of the donor in an experimental model.

We investigated the effect of donor pretreatment with chlorpromazine (CPZ), in rabbit livers cold-stored in University of Wisconsin (UW) cold storage solution for 48 hr. Three groups of livers were investigated: livers flushed with Perfadex and immediately thereafter reperfused on an isolated circuit (controls), and livers cold stored in UW solution for 48 hr, with or without donor pretreatment with CPZ, 3 mg/kg. After preservation, reperfusion was performed in vitro, using an isolated circuit (IPL). The reperfusion medium consisted of an oxygenated Krebs-Henseleit bicarbonate solution supplemented with 5 mM glucose, 50 mg/L of streptomycin and penicillin G, and 3.5% Dextran 60 for oncotic support. Livers that were not pretreated with CPZ produced 5.3 +/- 1.2 ml bile/100 g (mean +/- SD) during 2 hr of IPL reperfusion. CPZ donor pretreatment significantly improved the bile flow to 17.1 +/- 6.9 ml (P less than 0.01, Wilcoxon). This figure was not different from that in control livers without a storage period (18.3 +/- 3.8 ml). Alanine aspartate aminotransferase (ASAT) released into the perfusate was measured, and levels were increasing during 2 hr of reperfusion. ASAT values were moderately increased in the preserved groups compared with controls (P less than 0.01), with no discernible differences between livers with and without CPZ pretreatment. It is concluded that CPZ pretreatment of the donor improves preservation quality, as evidenced by improved bile formation. The present results suggest that 48 hr cold storage in UW solution may be safe for clinical preservation, if donors are pretreated with chlorpromazine.

Adenosine↗
PubMed1989

Acute ischemic liver failure in the rat: a reproducible model not requiring portal decompression.

We report a model of acute ischemic liver failure which does not require temporary or permanent portal decompression. The model is induced by segmental ischemia of the median and left lateral lobes for 100 min by a vascular clamp applied on the afferent vessels. Declamping is followed by resection of the nonischemic right lateral and caudate lobes. No portal stasis occurs as blood flow to the right lateral and caudate lobes is maintained during the period of clamping. The 24-hour mortality is 76.5%. Evidence of severe liver damage is shown by histological and biochemical studies.

Acute Disease↗
PubMed1989

Thioacetamide- and carbon tetrachloride-induced liver cirrhosis.

Two methods of inducing liver cirrhosis in the rat were studied. Intragastric administration of CCl4 for 16 weeks according to Proctor and Chatamra was compared to the administration of thioacetamide in the drinking water (0.3 g/l) for the same period. CCl4 administration induced micronodular cirrhosis in 6/8 animals with a 27% mortality. Thioacetamide induced cirrhosis in 6/8 animals without mortality. The histologic pictures differed somewhat in that the CCl4 group exhibited more necrosis and cellular swelling while the thioacetamide group had more nuclear atypias and proliferation. Biochemically both groups had elevated plasma levels of aspartate aminotransferase. The lysosomal enzyme beta-hexosaminidase (beta-NAG) showed a transient increase in the thioacetamide animals, while beta-glucuronidase decreased. CCl4-induced cirrhosis led to an increase in beta-NAG. Plasma zinc decreased in both groups as well as liver zinc content in the CCl4 group, while there was a continuous elevation of liver zinc in the thioacetamide group. We conclude that oral administration of thioacetamide is a simple and reliable method of inducing experimental liver cirrhosis. The differences in histological appearances and some biochemical parameters may be caused by the different mechanisms of action of thioacetamide and CCl4.

Acetamides↗
PubMed1989

Increased gut permeability to fluorescein isothiocyanate-dextran after total parenteral nutrition in the rat.

Sepsis with subsequent multiple organ failure is the commonest complication seen in the surgical intensive care unit today. A gut mucosal barrier dysfunction is assuming an increasingly important role as one possible explanation for the initiation of the septic process. It is known that the gut bacteria and endotoxins can, in the presence of a seemingly intact epithelium, translocate to extraintestinal sites, but the exact mechanism behind this process is not understood. In the present study we have approached this problem by testing the gut permeability to two macromolecules, bovine serum albumin (BSA) and fluorescein isothiocyanate (FITC)-dextran, after 7 days of enteral or parenteral nutrition in the rat. The plasma values of FITC-dextran after 4 h of marker feeding showed a significant increase in gut permeability after parenteral but not after enteral nutrition as compared with the controls. The plasma values of BSA, however, did not show any significant change in any of the groups. Thus, parenteral nutrition, with the changes occurring in the gut mucosa, may be one of the etiologic co-factors behind a gut mucosal barrier dysfunction, eventually leading to absorption of noxious agents into the systemic circulation with subsequent multiple organ failure.

Animals↗
PubMed1989

Influence of dextran on blood clearance and organ distribution of radiolabelled E. coli and on survival in experimental E. coli septicemia.

Previous reports indicated impaired function of the reticuloendothelial system following administration of dextran. In the present experimental study, intravenous injection of Escherichia coli resulted in four deaths among 15 rats pretreated with i.v. dextran 70, but none in 15 controls (p less than 0.05). To evaluate the influence of dextran on bacterial clearance from blood and distribution in organs, 125I-labelled, heat-killed E. coli was injected 1 or 24 hours following i.v. injection of 1.0 ml sterile saline solution or 1.0 ml dextran 70. After both of these intervals, dextran resulted in significant (p less than 0.05) decrease of blood clearance compared with the controls. The organ distribution in counts/minute (cpm)/g tissue was compared in liver, spleen and lungs. Splenic uptake was reduced at both times following dextran administration, while there was increase in pulmonary uptake at 1 hour and in hepatic uptake at 24 hours post-dextran (p less than 0.005 and p less than 0.02, respectively). Evaluation of cpm/total organ weight showed no change after dextran injection, except for increased (p less than 0.05) pulmonary uptake after 1 hour.

Animals↗