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Biomedical subjects

L Thulin

Publications and source records attributed to L Thulin.

At least 37 records · Page 2Linked to original sources
PubMed1985

Correlation between fluorescein flowmetry, 133Xenon clearance and electromagnetic flow measurement: a study in the intestine of the pig.

The purpose of the present study was to compare fluorescein flowmetry as a technique for measuring changes in intestine blood flow with electromagnetic blood flowmetry and the 133Xenon clearance technique. In eight anaesthetized pigs the blood flow in the superior mesenteric artery was reduced to 20-75% of basal flow as defined by electromagnetic flowmetry. The change in blood flow as calculated by fluorescein flowmetry correlated well with that obtained by electromagnetic blood flowmetry (correlation coefficient 0.86) and 133Xenon clearance technique (correlation coefficient 0.94). These findings indicate that fluorescein flowmetry can be considered a quantitative method for measurements of a relative blood flow.

Animals↗
PubMed1985

Fluorescein flowmetry: a method for measuring relative capillary blood flow in the intestine.

The present work represents an attempt to develop a method for measuring relative blood flow in intestinal capillaries, by the use of sodium fluorescein (Na-F) as an indicator substance. The method is called fluorescein flowmetry (FF). A mathematical model was developed; blood flow was expressed as an index between the maximum fluorescence obtained during the first circulatory passage of Na-F and the rise time, defined as the time interval between 10 and 90% of the maximum fluorescence. The prerequisites for the mathematical model were tested in experiments in animals and man. The extraction of Na-F in the intestinal capillaries was found to be more than 99%. The ratio between the tissue clearance and uptake was found to be 0.0051, indicating no back flux. Experiments in man revealed that the rise time was proportional to the mean transit time and the mean transversal time of the bolus proper. The accuracy of FF was confirmed in man where the ratio between mucosal and serosal-muscular capillary blood flow was 2:1. From the results obtained, it appears that FF can be used as a method for measuring relative capillary blood flow in the intestine.

Animals↗
PubMed1985

Intestinal capillary blood flow studied with fluorescein flowmetry in hemorrhagically shocked rats.

The intestinal capillary blood flow in hemorrhagic shock was studied in 32 rats by fluorescein flowmetry (FF). FF implies the measurement of relative intestinal capillary blood flow, expressed as an index. Exsanguination to 35 mmHg for 180 min resulted in a heterogeneous fluorescence pattern with 51% difference in blood flow index between the areas with most and those with least fluorescence, compared with 14% in the control group. Following retransfusion of the shed blood, the difference in blood flow index between areas with most and least fluorescence was 54%, suggesting that the heterogeneous blood flow was not improved by retransfusion. Heterogeneity of the capillary blood flow in the intestines seems to be a phenomenon of hemorrhagic shock and FF to be a suitable method for studying this condition.

Animals↗
PubMed1984

Effect of two different preparations of somatostatin on intra-portal pressure in patients with liver cirrhosis.

Somatostatin has been found by most authors to reduce splanchnic blood flow and hepatic venous wedge pressure. High success rates in treating oesophageal varicose bleeding have been reported by some authors, while others have been unable to confirm these findings. A reason for the discrepancies might be that different preparations of somatostatin were used. Consequently, two preparations of somatostatin were administered to three cirrhotic patients as 60-min infusions at a dosage of 250 micrograms/h. The intra-portal pressure was measured before and during the infusions and found to be unaffected by both preparations. The findings suggest that previously demonstrated reductions in portal pressure may have been of brief duration, possibly due to vascular autoregulation.

Blood Pressure↗
PubMed1984

Effects of substance P and somatostatin on taurocholate-stabilized and CCK- or secretin-induced choleresis in the anesthetized dog.

Eleven anesthetized dogs were provided with a common bile duct fistula, and the gallbladder was excluded. After stabilization of the bile flow by intravenous infusions of taurocholate, various peptides were administered intravenously. Substance P (SP) decreased the output of hepatic bile, bile acids, sodium, potassium, and bicarbonate by about 50%. When SP was superimposed on cholecystokinin (CCK)- or secretin-induced choleresis, all CCK-induced effects were abolished, whereas SP had a less pronounced anticholeretic effect when choleresis was induced by secretin. Somatostatin (SST) decreased the output of hepatic bile, bile acids, sodium, potassium, and bicarbonate by about 25%. SST had no inhibitory effect on CCK- or secretin-induced choleresis. It is suggested that the principal mode of action of SST on bile flow is indirect by inhibiting the release of choleretic hormones, whereas SP is suggested to act directly on the hepatocytes.

Animals↗
PubMed1984

Comparison between fluorescein angiography and fluorescein microscopy.

Fluorescein angiography (FA), which implies that the tissue is reproduced in natural size, and fluorescence microscopy was compared in anesthetized normovolemic and hypovolemic rats in order to define the microscopic background to the fluorescence pattern obtained by FA. It was found that the fluorescence detected by FA by the use of sodium fluorescein as an indicator substance was emitted from the interstitial and intracellular compartments, including the intranuclear. Microscopy showed that sodium fluorescein was located extravascularly in the small intestine within 4 seconds after an intravenous injection. There was a 4 second interval between corresponding microscopic and macroscopic fluorescence pattern.

Angiography↗
PubMed1983

The effect of cimetidine on liver blood flow in anesthetized man.

In eight patients subjected to abdominal surgery, the effect of intravenous cimetidine (Tagamet) on hepatic arterial blood flow and portal blood flow was studied, utilizing electromagnetic blood flowmetry. Following cimetidine an increase in hepatic arterial blood flow concomitant with a decrease in mean arterial pressure were detected. Calculated hepatic artery vascular resistance was therefore significantly decreased by 28% after 2 min and 17% after 10 min. There was no change in portal blood flow. It is suggested that this effect of cimetidine is due to increased plasma histamine levels after acute H2 receptor blockade.

Abdominal Neoplasms↗
PubMed1983

A case of haemobilia following percutaneous liver biopsy treated by selective arterial embolization.

A case is reported of severe hemobilia following a percutaneous liver biopsy. Hepatic ultrasound and computed tomography showed evidence of blood in the bile ducts and gall bladder. A selective arteriography revealed extravasation of blood in the liver. The bleeding ceased following selective embolization of the damaged artery after embolization with spongostan through the catheter used for the arteriogram. Following the embolization no further signs of bleeding were noted and the patient recovered completely.

Adult↗
PubMed1983

Decision theory as an aid in the diagnosis of cholestatic jaundice.

Current literature was reviewed for studies on diagnostic value and risk to the patient of different diagnostic techniques in jaundice. It was found that few studies of diagnostic techniques were in fact prospective trials and that many materials were highly selected. Reported figures were used for calculating expected risks and benefits of different investigative strategies. Decision analysis, here applied to a problem not as yet studied with this technique, enable us to compare the outcomes of different strategies and to construct a simple plan for the rational choice of investigative procedures in patients with cholestatic jaundice. According to this plan, following history-taking, physical examination and simple laboratory tests, the investigation should proceed directly with fine-needle PTC whenever the probability of extrahepatic cholestasis is judged to be greater than 87%, and with liver biopsy if this probability is judged to be lower than 2%. In all other cases further investigations should start with ultrasonography.

Cholestasis↗
PubMed1982

Peritoneovenous shunting for intractable ascites.

Ten patients with intractable ascites were treated with the LeVeen peritoneovenous shunt. Of these, three died perioperatively. Three patients with malignant ascites died within 2-3 months, but with good shunt function. In four patients, the shunt became occluded, after 2 weeks to 8 months. Percutaneous puncture of the shunt and injection of radiopaque dye revealed the occlusion t be due to thrombosis of the venous limb of the shunt. In one patient, superior vena cava thrombosis occurred. Another ten patients were treated with the Denver peritoneovenous shunt. One patient died perioperatively; four patients with malignant ascites and one with cirrhosis died after 11 days-3 months, but with good shunt function. One patient with cirrhosis is alive after 5 months, with good function. In three patients the shunt became occluded after 5 days-1 month but two of these could be cleared with the fluschchamber of the Denver shunt. It seems that the Denver shunt functions better than the LeVeen shunt, and that the primary indication for peritoneovenous shunting is malignant ascites. Here palliation is excellent. No patient developed clinical signs of disseminated intravascular coagulation following ascites infusion and in six patients where coagulation variables were studed, there were no signs of a consumption coagulopathy.

Ascites↗
PubMed1981

The effect of somatostatin on blood flow through coronary bypass grafts in anesthetized man.

The effect of intravenous somatostatin on blood flow through coronary bypass grafts was studied in 12 patients subjected to aorto-coronary bypass surgery. Aorto-coronary bypass blood flow was determined by means of electromagnetic blood flowmetry. No change was observed in the bypass blood flow, either during or after intravenous somatostatin at doses of 100 microgram/h and 250 microgram/h. These findings suggest that somatostatin has no effect on coronary haemodynamics in man.

Aged↗
PubMed1981

Effects of substance P and somatostatin on choleresis in anesthetized dogs.

Six anesthetized dogs were administered three consecutive 30 min infusions of substance P in increasing doses of 1.0, 2.5 and 20 ng kg(-1) min (-1). Five anesthetized dogs were administered 10 min infusions of somatostatin, 0.2 and 1.0 microgram kg(-1) min(-1). The dogs were provided with a common duct fistula and the cystic duct was ligated. The output of total bile, bile acids, sodium, potassium, chloride and bicarbonate was studied in 10 min fractions. Substance P at a dose of 2.5 ng kg(-1) min(-1) and above, reduced the output of total bile, sodium, potassium and chloride by a maximum of 40%, indicating an inhibition of the bile acid independent fraction. The output of bile acids and bicarbonate was unaffected. Both doses of somatostatin reduced all parameters studied by a maximum of 25-45%, indicating inhibition of the bile acid dependent, the bile acid independent and the ductular bile secretion.

Animals↗
PubMed1981

Effect of carotid endarterectomy on the antihypertensive properties of the carotid sinus reflex.

In eight patients subjected to carotid reconstructive surgery, the reflex effect on systemic pressure of an increase in carotid sinus transmural pressure was studied, before and two months after endarterectomy. The increase in carotid sinus transmural pressure was obtained by applying subatmospheric pressure to the neck. It was found that the closed loop gain of the carotid sinus reflex, calculated as the ratio of change in systemic pressure to change in carotid sinus transmural pressure, was 0.53 before and 0.52 two months after endarterectomy. It is thus concluded that carotid endarterectomy has no persisting effect on the antihypertensive properties of the carotid sinus reflex.

Blood Pressure↗