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Biomedical subjects

J Svanvik

Publications and source records attributed to J Svanvik.

At least 19 recordsLinked to original sources
PubMed1995

Role of nitric oxide in motility and secretion of the feline hepatobiliary tract.

BACKGROUND: Nitric oxide (NO) mediates inhibition of gastrointestinal smooth-muscle cells via nonadrenergic, non-cholinergic (NANC) nervous pathways. The effect of NO on the absorption and secretion by the mucosa of the gastrointestinal and hepatobiliary tracts is less well known. The aim of this study was to evaluate the effects of a pharmacologic blockade of NO synthase on sphincter of Oddi activity, gallbladder function, and bile secretion and to demonstrate the presence of NO synthase-positive neurons in this region. METHODS: Experiments were conducted on anesthetized cats after blockage of noradrenergic and cholinergic neurotransmission. Flow resistance in the sphincter of Oddi, gallbladder fluid absorption and motility, bile outflow from the liver, and bile salt secretion were registered. RESULTS: Flow resistance exerted by the sphincter of Oddi increased dose-dependently in response to the NO synthase blocker NG-nitro-L-arginine. The increase in flow resistance was reversed stereospecifically by L-arginine, the substrate for NO synthesis. No significant effects on bile secretion, gallbladder fluid transport, or gallbladder motility were observed. NO synthase-positive neurons were identified close to the sphincter of Oddi and in the gallbladder mucosa. CONCLUSIONS: This tonically active inhibitory NANC innervation of the sphincter of Oddi may be important in the physiologic regulation of the bile duct pressure.

Animals↗
PubMed1995

A comparative retrospective study of thoracoscopy versus thoracotomy for the treatment of spontaneous pneumothorax.

Thoracoscopic surgery has been claimed to reduce patient disability, recovery time, and hospital costs compared with open surgery. We analyzed 25 patients who had undergone thoracoscopic surgery and compared the outcome to 24 patients who had undergone conventional surgery for spontaneous pneumothorax. The thoracoscopic group was able to return to work and daily activities earlier and had less impairment of shoulder movement. There was a loss of sensation corresponding to the dermatomes where the thoracoscopic ports were placed, which could have resulted from compression of the intercostal nerves by the instruments. However, a similar loss of sensation was found in the thoracotomy group. We conclude that thoracoscopy may be the method of choice for the treatment of spontaneous pneumothorax, although further methodological development should be done.

Activities of Daily Living↗
PubMed1994

VIP-antiserum inhibits fluid secretion by the inflamed gallbladder mucosa.

The inflammatory fluid secretion by the gallbladder mucosa in experimental cholecystitis is induced by an increased prostaglandin formation and is mediated by intramural nerves. In the present study the effect of VIP-antiserum on the inflammatory fluid secretion in the gallbladder was tested in a validated experimental model in cats. The animals were studied in acute experiments 6 weeks after a procedure when the cystic duct was tied and gallstones were implanted in the gallbladder. During basal conditions there was a continuous secretion of fluid into the lumen of the inflamed gallbladder averaging 0.43 +/- 0.18 ml/h. Injection of VIP antiserum, obtained from immunized rabbits and diluted with saline 1:10 in a bolus of 4 ml into the coeliac artery reversed this secretion into an absorption of 1.72 +/- 0.44 ml h-1 (P < 0.001). VIP-antiserum did not affect the fluid adsorption in control animals with an intact gallbladder and injection of control serum from rabbits not immunized to VIP did not affect fluid secretion in the inflamed gallbladders. The results support the idea that the inflammatory fluid secretion in the gallbladder mucosa is mediated by VIP-ergic nerve fibres.

Animals↗
PubMed1994

Raised pressure in the bile ducts after orthotopic liver transplantation.

Biliary complications are common after orthotopic liver transplantation. Bile leakage in the immediate postoperative period and on removal of the T-tube could possibly be caused by a raised bile duct pressure. In order to test this hypothesis, bile duct pressure was studied in seven consecutive liver transplant patients. During the operation, the common bile duct was anastomosed end-to-end over a T-tube. The initial bile duct pressure measurement was performed a median of 12 days (range 10-17 days) after the transplantation and on one or two more occasions during the following 3 months. Seven cholecystectomized gallstone patients with indwelling T-tubes were used as controls. The bile duct pressure at the level of the xiphoid process in the transplanted group was 7.7 +/- 1.4 cm H2O and in the control group 0.5 +/- 0.8 cm H2O (P < 0.001). The initially increased bile duct pressure after liver transplantation decreased with time (P < 0.05) towards normal during the following 3 months. The raised pressure may increase the risk of bile leakage in the postoperative period.

Adult↗
PubMed1994

A possible role of ursodeoxycholic acid in liver transplantation.

There are many different causes of graft dysfunction and cholestasis after liver transplantation. These include non-primary function, preservation and reperfusion injury, acute rejection, artery thrombosis, drug toxicity, bile leakage, and bile duct stenosis. Medication with ursodeoxycholic acid (UDCA) has beneficial effects in different cholestatic conditions. The initial rationale for its use after liver transplantation was to alter the bile acid pool to a more atoxic composition, as liver transplantation can be associated with cholestasis and can stimulate the initial bile production. We have consecutively treated 41 patients with primary graft function with UDCA. During the first postoperative month, 17% of the UDCA treated patients had an episode of acute rejection compared with 75% of a historical control group of 8 patients. The results suggest that adjuvant treatment with UDCA reduces acute liver graft rejection. This has to be confirmed by controlled prospective trials; one is presently being carried out in the Nordic countries. Several studies have indicated an immunomodulating capacity of this bile acid and we have recently reported our results from a heart transplant model in the rat, where treatment with UDCA prolonged graft survival. Improvement in surgical technique and postoperative care as well as immunosuppressive treatment has improved the results of liver transplantation. Acute rejection is nowadays a dominating problem after liver transplantation and the inclusion of UDCA may reduce morbidity.

Animals↗
PubMed1993

In vivo regulation of mucosal transport of H+ and HCO3- in the feline gall bladder.

In the gall bladder of a fasting subject, a decline in the pH of the contents occurs due to secretion of H+ from the mucosa. In this study in anaesthetized cats, the gall bladder lumen was perfused with a bicarbonate buffer bubbled with 4% CO2 in air. During basal conditions, the PCO2 always rose while the pH and [HCO3-] fell in the buffer when passing through the gall bladder lumen, indicating a continuous secretion of H+ by the mucosa. This H+ secretion was enhanced by stimulation of the respective sympathetic nerves and was blocked by intraluminal amiloride. Intravenous infusion of vasoactive intestinal peptide (VIP) raised the pH and [HCO3-] in the buffer during the passage through the gall bladder lumen, indicating a secretion of bicarbonate from the mucosa. In view of the presence of sympathetic and VIP immunoreactive nerve fibres in the gall bladder wall and VIP receptors on the luminal epithelial cells, the study demonstrates that there are functional grounds for physiological variations in the secretion of H+ and HCO3- by the gall bladder mucosa. These variations may be important for the solubility of calcium salts in the gall bladder contents.

Amiloride↗
PubMed1993

Contraction and evacuation of the gallbladder studied simultaneously by ultrasonography and 99mTc-labeled diethyl-iminodiacetic acid scintigraphy.

Emptying of the gallbladder was studied by the simultaneous use of 99mTc-labeled diethyl-iminodiacetic acid [HIDA] scanning and real-time ultrasonography. In response to a liquid test meal the gallbladder volume was reduced for 80 min and then increased again, but the radionuclide evacuation continued and was more complete than could be explained by the reduction of gallbladder volume. In response to intravenous infusion of cholecystokinin, a maximal contraction of the gallbladder to 35% of the basal volume was obtained at 40 min, and 36% of the HIDA then remained in the gallbladder. In a separate series repeated intravenous injections of 99mTc-HIDA were given after the test meal, and the isotope was found to enter the gallbladder even when the gallbladder contracted. The results support the view that the gallbladder acts like a 'bellows' when contracting and that postprandial fluid secretion by the gallbladder mucosa may help to evacuate its contents.

Adult↗
PubMed1992

Location of enkephalinase and functional effects of [Leu5]enkephalin and inhibition of enkephalinase in the feline main pancreatic and bile duct sphincters.

1. Morphological studies have demonstrated enkephalinergic nerve fibres in proximity to the sphincter of Oddi, and opiates are known to contract this sphincter. In this study, the flow resistances in the common bile duct and main pancreatic duct sphincters were studied simultaneously in anaesthetized cats using a perfusion technique. 2. Naloxone did not affect the activity of these sphincters under basal conditions, indicating that there is no basal enkephalinergic tone. 3. The response to [Leu5]enkephalin (0.015-15 micrograms/kg), morphine (1 mg/kg) and ketamine (10 mg/kg) was a naloxone-sensitive increased activity in the sphincters with a raised frequency of phasic contractions. The threshold dose for an effect of [Leu5]enkephalin on the sphincter of Oddi was 0.015 microgram/kg and a maximal response was observed at 0.75 microgram/kg. There were no differences in the response of the main pancreatic duct sphincter and the bile duct sphincter to the different drugs. 4. Immunoautoradiographic studies demonstrated enkephalinase in the sphincter++ of Oddi. 5. Acetorphan (3 mg/kg intravenously), which inhibits endogenous enkephalinase both in the peripheral and the central nervous system when administered parenterally, caused a naloxone-sensitive contraction, whereas thiorphan (3-20 mg/kg), an enkephalinase inhibitor that does not easily penetrate the blood-brain barrier, had no effect on the sphincter of Oddi. 6. These results show that endogenous and exogenous opiates influence the function of the feline sphincter of Oddi and that enkephalins may be involved in the physiological control of this sphincter, although not under basal conditions.

Animals↗
PubMed1991

Effect of short-term indomethacin treatment on the clinical course of acute obstructive cholecystitis.

In acute obstructive cholecystitis the increased intraluminal pressure in the gallbladder is reduced by nonsteroid anti-inflammatory drugs which effectively relieve biliary pain. To investigate if such drugs influence the clinical course, a double-blind study was performed in which indomethacin (suppositories 75 mg b.d.) was tested against placebo in 34 patients with acute obstructive cholecystitis. During the 3-day treatment period both the indomethacin and the placebo group improved significantly as regards pyrexia, pain, abdominal tenderness and leukocytosis. The indomethacin group showed significantly greater improvement than the placebo group in temperature, pain and white blood cell count on day 1, and significantly greater reduction of abdominal tenderness on day 2. The serum bilirubin fell significantly during the 3-day period in the indomethacin, but not the placebo group. The hospital stay in cases without early surgery was significantly shorter in the indomethacin group (5.4 vs. 8.5 days). Because of its favourable effect on the clinical course of acute cholecystitis, rectally administered indomethacin is useful for patients awaiting operation or scheduled for later elective surgery.

Acute Disease↗