Substrate oxidation by the portal drained viscera of fed piglets.
(33/2024)
Fully fed piglets (28 days old, 7-8 kg) bearing portal, arterial, and gastric catheters and a portal flow probe were infused with enteral [U-(13)C]glutamate (n = 4), enteral [U-(13)C]glucose (n = 4), intravenous [U-(13)C]glucose (n = 4), or intravenous [U-(13)C]glutamine (n = 3). A total of 94% of the enteral [U-(13)C]glutamate but only 6% of the enteral [U- (13)C]glucose was utilized in first pass by the portal-drained viscera (PDV). The PDV extracted 6.5% of the arterial flux of [U-(13)C]glucose and 20.4% of the arterial flux of [U-(13)C]glutamine. The production of (13)CO(2) (percentage of dose) by the PDV from enteral glucose (3%), arterial glucose (27%), enteral glutamate (52%), and arterial glutamine (70%) varied widely. The substrates contributed 15% (enteral glucose), 19% (arterial glutamine), 29% (arterial glucose), and 36% (enteral glutamate) of the total production of CO(2) by the PDV. Enteral glucose accounted for 18% of the portal alanine and 31% of the portal lactate carbon outflow. We conclude that, in vivo, three-fourths of the energy needs of the PDV are satisfied by the oxidation of glucose, glutamate, and glutamine, and that dietary glutamate is the most important single contributor to mucosal oxidative energy generation. (+info)
Impaired stimulation of intestinal glucose absorption via hepatoenteral nerves in streptozotocin-diabetic rats.
(34/2024)
In an ex situ organ perfusion system, that of the isolated nonrecirculating joint perfusion of rat small intestine and liver, insulin infused into the portal vein increased intestinal glucose absorption. This insulin action against the bloodstream can be blocked by TTX, indicating a propagation of the insulin signal via hepatoenteral nerves, which conforms with previous studies with atropine and carbachol. Insulin action could also be mimicked by dibutyryl cAMP (DBcAMP) acting directly on the absorptive enterocytes. Because autonomic neuropathy is a common late complication of diabetes mellitus, the possible impairment of these nerves in the diabetic state was studied in streptozotocin-diabetic rats. In the isolated joint intestine-liver perfusion, glucose was applied as a bolus into the lumen; its absorption was measured in the portal vein. In 5-day diabetic as well as in control rats, portal insulin, arterial carbachol, and arterial DBcAMP increased intestinal glucose absorption. In 3-mo diabetic rats portal insulin and arterial carbachol failed to stimulate glucose absorption, whereas arterial DBcAMP still did so, indicating an undisturbed function of the absorptive enterocytes. The lack of an effect of portal insulin and arterial carbachol and the unchanged action of DBcAMP in the chronically diabetic rats indicated that the signaling chain via the hepatoenteral nerves was impaired, which is in line with a diabetic neuropathy. (+info)
Hepatic manifestations of familial patent ductus venosus in adults.
(35/2024)
BACKGROUND: The ductus venosus connects the umbilical vein to the inferior vena cava during fetal life and subsequently closes rapidly after birth. It is known as patent ductus venosus when it remains patent in adulthood. PATIENTS: A 43 year old man with a history of panhypopituitarism presented with recurrent bouts of pedal oedema associated with fatigue, hypoalbuminaemia, and elevated prothrombin time. An ultrasound examination of his abdomen with Doppler revealed notable attenuation of the main portal vein with diminished intrahepatic branches; a computed tomography scan with angiography revealed a large collateral vein within the liver consistent with a patent ductus venosus. Sequential liver biopsies showed a considerable reduction in the calibre and number of the portal veins. His younger brother, who was diagnosed with alcohol related cirrhosis, suffered from intermittent bouts of encephalopathy and was found to have the same vascular lesion. A third brother was found to have a patent ductus venosus as well as two large hepatic masses consistent with focal nodular hyperplasia. CONCLUSION: The syndrome of familial patent ductus venosus has only previously been described in three infant brothers who presented with hepatic encephalopathy and fatty degeneration of the liver. This report documents three brothers with a patent ductus venosus presenting in adulthood with different manifestations of liver disease. The presence of the same vascular anomaly in three brothers is highly suggestive of a recessive genetic trait with an anatomical manifestation of patent ductus venosus. (+info)
Results of a modified sugiura's devascularisation in the management of "unshuntable" portal hypertension.
(36/2024)
The results of a modified Sugiura devascularisation procedure were assessed in 14 patients with thrombosis of the portal and splenic vein requiring surgery for variceal hemorrhage, with no vein suitable for orthodox shunt surgery. The venous anatomy was determined by ultrasonography with Doppler studies and portovenography. Liver biochemistry as well as liver architecture on histopathology was normal in all. The surgery was elective in 9 cases for documented bleed from diffuse fundal gastric varices (FGV) and emergency in 5 cases, 3 having bleeding FGV and 2 for failure of emergency esophageal variceal sclerotherapy. All were subjected to a transabdominal extensive devascularisation of the upper two third of the stomach and lower 7-10cm of the esophagus. Stapled esophageal transection (n = 11) or esophageal variceal underrunning (n = 1) was performed in all with esophageal varices. FGV were underrun. Follow up endoscopies were done six monthly. There were 9 males and 5 females with a mean age of 17.2 years (SD 12.8). There was no operative mortality. Acute variceal bleeding was controlled in all patients. Over a mean follow up of 38 months, all but one remain free of recurrent bleeding. We conclude that a modified Sugiura devascularisation procedure is effective in the immediate and medium term control of variceal bleeding in patients with "unshuntable" portal hypertension. (+info)
Arterialisation of the portal vein with an aortoportal jump graft for portal vein thrombosis following liver resection for malignancy.
(37/2024)
Fibrolamellar hepatocellular carcinoma (FHCC) is a variant of hepatocellular carcinoma, which mainly affects a young age group and carries a relatively good prognosis. It is widely accepted that aggressive curative resection is still the best option for FHCC. We report here a case of successful arterialisation of the portal vein with an aortoportal jump graft for portal vein thrombosis, which developed postoperatively in an already comprised portal vein with tumour invasion following an extensive liver resection for FHCC. (+info)
Long-term haemodynamic effects of octreotide on postprandial splanchnic hyperemia in humans: a placebo-controlled echo-doppler study.
(38/2024)
BACKGROUND: Octreotide is a potent splanchnic hypotensive somatostatin analogue effective in the treatment of acute variceal bleeding. AIM: To study the effects of octreotide on basal and postprandial splanchnic and systemic haemodynamics, and hormonal changes in humans. METHODS: Twenty-four healthy volunteers were randomized to receive a liquid meal and either octreotide (OCT, 100 microg bolus) or placebo repeatedly every 4 h for 48 h. Splanchnic (Doppler ultrasound) and systemic haemodynamics (non-invasive cardiac monitoring) were assessed for 2 h on four consecutive days: one control day and after doses 1 (0 h), 7 (24 h) and 13 (48 h). RESULTS: The maximum postprandial increases in mean blood velocity of the superior mesenteric artery (SMA-Vmean +72%), portal (PBF +52%) and total hepatic blood flow (HBF +50%) observed in the placebo group, were abolished after the first dose of octreotide (SMA-Vmean -23%, P<0.01; PBF -22%, P<0.01; HBF -21%, P<0.01). Postprandial hyperemia was restored at the end of the 48-h study period, but baseline SMA-Vmean (placebo 40+/-12, OCT 29+/-11 cm/s, P<0.05) and PBF (placebo 1200+/-971, OCT 743+/-449 mL/min, P<0.05) remained significantly lower in the octreotide group. The postprandial decrease of systemic vascular resistance and increase of cardiac index were prevented by octreotide for 48 h. CONCLUSIONS: Repeated 4-hourly bolus injections of octreotide reduce splanchnic blood flow for at least 48 h, but the prevention of food-induced splanchnic hyperemia is short-lasting. (+info)
Laminin mediates tethering and spreading of colon cancer cells in physiological shear flow.
(39/2024)
Under the physiological shear condition, cultured colon cancer cells bound to laminin (LM), but not to fibronectin or vitronectin. Most of the tethered cells did not roll, but arrested immediately and spread within 10-30 min on LM under the continuous presence of shear flow. The tethering of Colo201 was partially inhibited by monoclonal antibodies (mAbs) to alpha6 integrin and a combination of mAbs to beta1 and beta4 integrins, but not by mAb to 67KD laminin receptor. Some Colo201 cells still tethered at 4 degrees C. This suggests that alpha6beta1 and alpha6beta4 integrins participate in Colo201 tethering on LM, although other non-integrin molecules play roles. In contrast, the spread of Colo201 was effectively inhibited by the mAbs to integrin alpha2, alpha6 and beta1 chains. The effect of anti-alpha2 plus anti-alpha6 mAbs was almost equal to anti-beta1, suggesting that Colo201 cells mainly use alpha2beta1 and alpha6beta1 integrins for spreading on LM. When the cells were perfused on subconfluent endothelial cells (HUVEC) cultured on LM, they did not tether on HUVEC but did on coated LM exposed at intercellular gap area. Immunohistochemistry revealed that LM abundantly existed in the cytosol of human portal and hepatic vein endothelial cells. These data suggest that LM can mediate from tethering to spreading of colon cancer cells under the blood flow and plays an essential role in haematogeneous metastasis. (+info)
Mesenteric and portal vein thrombosis in a young patient with protein S deficiency treated with urokinase via the superior mesenteric artery.
(40/2024)
A 32-year-old man, who was previously healthy, had acute abdominal pain without peritonitis. Diffuse mesenteric and portal vein thrombosis were shown by means of a computed tomography scan. A protein s deficiency was found by means of an extensive workup for hypercoagulable state. Successful treatment was achieved with urokinase infusion via the superior mesenteric artery without an operation. This represents an attractive alternative approach to treating patients with this disease. The previous standard of operative intervention(1) can now be reserved for complications, such as bowel infarction with peritonitis, or for those patients with absolute contraindications to thrombolytic therapy. (+info)