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Biomedical subjects

S Bengmark

Publications and source records attributed to S Bengmark.

At least 181 records · Page 10Linked to original sources

Ischaemic and metabolic treatment of hepatic tumours.

For treatment of malignancies, physical and metabolic differences between tumour cells and host cells have guided the development of new approaches. In this review, two new approaches to be used in the treatment of liver malignancies are outlined: ischaemic therapy and interferences with the glucose metabolism. Ischaemic therapy of liver malignancies has been used in different forms during the last 20 years: from ligation of the hepatic artery, embolization of the arterial tree, transient occlusion of the hepatic artery to the present day use of temporary, intermittent, transient hepatic arterial occlusion. The beneficial effect of ischaemic therapy on malignancies is supposed to depend on oxygen and nutritional deficiency, formation of oxygen-derived free radicals and loss of function in cellular enzymes. The tumour cells seem thereby to be more sensitive than the host cells. Also, ischaemia might potentiate the effect of cytotoxic drugs. Intereferencies with glucose metabolism might be directed either towards the exaggerated tumour glycolysis, for example by glucose analogues like 2-deoxy-glucose, or towards the exaggerated host gluconeogenesis, for example by hydrazine sulphate. These treatments result in reduction of the glucose availability in the intracellular glucose metabolism in the tumour cells and have experimentally been demonstrated to be correlated to reduced tumour growth. It is concluded that both these approaches, ischaemic therapy and manipulations with the glucose metabolism, seem promising for the future. What is needed now is research to clarify the mechanisms behind the effects, to establish their full consequences, and to identify the clinical use of these treatments and their possible combinations.

Glucose↗

Hemoperitoneum after spontaneous rupture of liver tumor: results of surgical treatment.

Five cases of massive hemoperitoneum caused by spontaneous rupture of liver tumors, collected during a 27-year period, are reported. Four patients had a primary liver malignancy and one patient a liver cyst with hemangioma. Initial symptoms were obscure and hemoperitoneum was suspected pre-operatively in only one patient. At operation, a mean of 3100 ml of blood was found in the abdomen. Hemostatis was achieved by liver resection in four patients and by suture ligation in one. Two patients died during or shortly after operation. The three patients surviving the operation had primary liver cancer and lived for 6 months to 6.5 years. It is concluded that liver resection, whenever possible, is the treatment of choice and that pre-operative delay and mortality may be diminished by increased awareness of this condition.

Aged↗

RNA labelling with 3H-orotic acid and 3H-fluorouracil of rat liver tumour following transient hepatic arterial ischaemia.

Recent studies have demonstrated that transient (1 h) hepatic arterial ischaemia is followed by increased incorporation of labelled thymidine into tumour DNA 24 h later. The present study aimed at investigating if and when there is a corresponding increase in incorporation of labelled 5-fluorouracil (5-FU) or orotic acid into tumour tissue. Incorporation was studied at 0, 6, 24 and 48 h after discontinuation of transient hepatic arterial ischaemia in Wistar-Furth rats having liver tumour. The transient ischaemia was followed by increased RNA and RNA/DNA ratios in normal liver but not in tumour. Incorporation of orotic acid into RNA and DNA was unchanged in tumour but increased at 0 and 6 h in normal liver. Incorporation of 5-FU decreased with time in liver and tumour DNA and in tumour RNA. It is suggested that 5-FU has an optimal effect on tumour tissue when infused immediately after transient hepatic arterial ischaemia.

Animals↗

Surgical treatment of cavernous hemangioma of the liver.

Cavernous hemangioma of the liver was surgically treated in six men and two women, mean age 58 (51-63) years during a 37-year period. The size of hemangioma averaged 10 (5-15) cm. It was single in all cases and situated in the right liver lobe in seven. The indications for operation were suspected abdominal tumor or hepatic metastases in five cases, enlargement of previously known hemangioma in two, and spontaneous rupture of cavernous hemangioma with massive intra-abdominal bleeding in one case (emergency laparotomy). The operations comprised two right lobectomies, one left lobectomy, three atypical resections of the right liver lobe and two sublobar resections. The course after the elective operations was uneventful, but the patient with ruptured hemangioma died intraoperatively due to myocardial fibrillation after performance of right lobectomy. Although elective surgical treatment of cavernous hemangioma of the liver is safe, the natural history in most cases probably is benign and indications for surgery should be restrictive.

Female↗

Influence of dextran on pneumococcal septicemia in splenic artery-ligated or splenectomized rats.

Splenic artery ligation is one of several methods in splenic preservation. In this experimental work the susceptibility of splenectomized rats and rats treated with splenic artery ligation to pneumococcal infection and the influence of the plasma expander dextran in the same groups were studied. The mortality among splenectomized rats was 100% vs nil after sham operation. Animals treated with splenic artery ligation and saline had a 23% mortality in pneumococcal septicemia, significantly different (P less than 0.05) from the 59% mortality after splenic artery ligation and dextran. A significant increase (P less than 0.05) in number of abscesses was also seen among rats given dextran.

Abscess↗

Effect of acetaldehyde on rat platelet aggregation in vivo and in vitro.

The effect of acetaldehyde on primary hemostasis and platelet aggregation was studied in vivo and in vitro in the rat. Acetaldehyde was found in circulation following ethanol intoxication or was present after direct i.v. injection. In vitro, acetaldehyde was added to whole blood or platelet plasma suspension. Bleeding time and blood loss were increased upon ethanol intoxication and immediately after i.v. infusion of acetaldehyde. The intrinsic coagulation system, assayed by APT-time, was unaffected. In vivo, ADP and collagen-induced platelet aggregation was inhibited upon the presence of acetaldehyde. In vitro, inhibition of platelet aggregation was observed when acetaldehyde was added to blood, while the addition of the compound to plasma did not affect platelet function.

Acetaldehyde↗

Control of traumatic liver hemorrhage in the cirrhotic rat by intraportal infusion of norepinephrine.

The effect of intraportal infusion of norepinephrine (NE) on primary hemostasis in the cirrhotic rat was investigated at standardized liver trauma. Cirrhosis was induced by simultaneous administration of increasing amounts of carbontetrachloride (CCl4) and phenobarbitone. Infusion of norepinephrine took place after cannulation of the gastroduodenal vein. Intraportal infusion of NE resulted in a significant increase in arterial blood pressure and portal pressure in all animals. No difference was observed between cirrhotic and control rats. Cirrhotic animals bled longer and more profusely as compared with the controls. Infusion of NE resulted in significant decrease in bleeding time and blood loss. NE did not affect hematocrit, hemoglobin, platelet, or white cell count. Platelet aggregation was not influenced by the compound. In conclusion, intraportal infusion of NE proved effective in decreasing hemorrhage at liver trauma in cirrhotic rats.

Animals↗

Increased uptake of 5-FU in experimental liver tumours by simultaneous infusion of norepinephrine.

The effect of the simultaneous administration of norepinephrine and 5-fluorouracil (5-FU) on the uptake of radiolabelled 5-FU by liver tumours was studied in rats. Three different concentrations of 5-FU were used (15, 1.5 and 0.15 microgram/g body weight). The drugs were infused over a 30 min period via the hepatic artery, following cannulation of the gastroduodenal artery. The radioactivity in liver tumour, normal liver, lungs and intestines was estimated by liquid scintillation counting. At all concentrations tested, an increased uptake of radioactive 5-FU was found in the tumour when norepinephrine was infused. Tumour/liver ratios also increased significantly in all these cases. No significant differences were noted between norepinephrine infused and control animals in the radioactivity in normal liver, lungs and intestines. The effects noted were possibly due to changes in blood flow within the liver, but the possibility of a direct effect of norepinephrine on DNA metabolism is discussed.

Animals↗

Early biochemical and histological changes in rats exposed to a single injection of thioacetamide.

Liver injury was induced by one subcutaneous administration of thioacetamide (200 mg/kg b.wt.) and studied 24 and 48 hrs later. Levels of aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT) increased after 24 and 48 hrs. The lysosomal enzymes beta-hexosaminidase (beta-NAG) and beta-glucuronidase (beta-GLU) increased significantly after 24 hrs, while the level of beta-GLU returned to normal after 48 hrs, but the activity of beta-NAG remained significantly high even after 48 hrs. Histopathological examination showed necrotic hepatocytes around the central vein with infiltration of macrophages, neutrophils and eosinophils. The plasma zinc level decreased after 24 hrs and returned to normal after 48 hrs. Liver zinc content increased simultaneously at 24 hrs, returning to normal after 48 hrs. No alterations of plasma copper were observed after 24 and 48 hrs. Copper content of the liver increased significantly after 24 and 48 hrs. The present study thus shows that one dose of thioacetamide results in profound liver injury and supplementation of zinc prior to and simultaneously with thioacetamide normalized plasma zinc, increased liver zinc content and reduced the increase of beta-NAG, but did not influence the histological changes.

Acetamides↗

Effect of intraarterial, intraportal or combined norepinephrine infusion on hemorrhage at experimental liver trauma in the rat.

The effect of intraarterial, intraportal or simultaneous intraarterial and intraportal norepinephrine (NE) infusion on hemorrhage after standardized liver trauma was evaluated in the rat. Infusion of NE through a catheter in the gastroduodenal artery or/and vein, was started 5 min prior to the liver trauma and continued throughout the experiment. Blood pressure was continuously registered after cannulation of the femoral artery. Standardized liver trauma involved resection of the left anterior liver lobe. Bleeding time, blood loss from the traumatized liver surface, hemoglobin (Hb), hematocrit (Hct), platelet count (PC) and white blood cell count (WBC) were measured. Infusion of NE resulted in significant increase of blood pressure compared with controls. Infusion of NE (i.a., i.p., i.a. + i.p.) caused significant decrease in bleeding time and blood loss. Hb, Hct, PC and WBC were not affected. NE infusion proved effective in decreasing hemorrhage at liver trauma; the route of administration did not influence the results.

Animals↗

Serum proteins in liver cirrhosis: effects of shunt surgery.

The serum protein patterns of 38 patients with alcoholic liver cirrhosis were studied and compared with those of 15 patients with cryptogenic cirrhosis and of 18 normal volunteers. Serum prealbumin and albumin were significantly lowered in alcoholic liver cirrhosis in comparison with the normals. In liver cirrhosis, the four acute phase reactants, alpha 1-antiproteinase, orosomucoid, and haptoglobin and caeruloplasmin, showed a pattern in serum, in which alpha 1-antiproteinase was increased, orosomucoid and haptoglobin were decreased, and caeruloplasmin was normal. Immunoglobulins G, A and M were significantly elevated. IgA was significantly more elevated in patients with alcoholic disease than in patients with cryptogenic cirrhosis. The construction of a surgical portal-systemic shunt resulted in a significant decrease in serum concentrations of the acute phase reactants, while prealbumin, albumin and immunoglobulins were unaffected.

Acute-Phase Proteins↗

beta-Hexosaminidase in plasma and liver after partial hepatectomy in normal and cirrhotic rats.

The liver and plasma level of the lysosomal enzyme beta-hexosaminidase was analyzed in partially (about 70%) hepatectomized rats with normal liver or carbon tetrachloride (CCl4)-induced cirrhosis. The enzyme level of the liver did not show marked changes after partial hepatectomy in either normal or cirrhotic rats. In contrast, the plasma basal level was significantly higher in cirrhotic rats and increased to a peak at 6 h, followed by a decrease to a minimum level 24 h after operation. The enzyme returned to its high plasma basal level at 36 h after partial hepatectomy, when the liver had recovered to 70% of its initial weight. In rats with normal liver the plasma beta-hexosaminidase showed another pattern, with a rapid increase at 6 h and thereafter gradually reaching a peak at 36 h after hepatectomy. We conclude that the cells responsible for increased plasma beta-hexosaminidase in cirrhotic rats are situated in the liver.

Alanine Transaminase↗