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Biomedical subjects

R Preisig

Publications and source records attributed to R Preisig.

At least 73 records · Page 4Linked to original sources

Aminopyrine demethylation measured by breath analysis in cirrhosis.

The method of measuring the rate of aminopyrine demethylation by breath analysis was assessed in 23 normal subjects and 20 patients with cirrhosis. Carbon 14 aminopyrine specifically labeled at the two N-methyl groups was administered by mouth in a dose of 9 mg/kg, including a total radioactivity of 2 muCi. The decay of the specific activity of 14CO2 in breath (kb) was found to correlate (r = 0.91) with the disappearance of aminopyrine from plasma (KP). In normal volunteers, kb was 22.4%/hr; in patients with alcoholic and nonalcoholic cirrhosis it was depressed to 8.4%/hr (p less than 0.001). The degree of functional impairment found with the breath test was similar to the sulfobromophthalein (BSP) disappearance curve and the galactose elimination capacity. Although many questions relating to the aminopyrine breath test remain open, our data confirm and extend previous studies of 14CO2 breath analysis after 14C-aminopyrine administration. It is concluded that it represents a simple and noninvasive procedure which quantitatively reflects the microsomal function of the cirrhotic liver.

Adult↗

Hepatic functional deterioration after portacaval shunt in the rat. Effects on sulfobromophthalein transport-maximum, indocyanine green clearance and galactose elimination capacity.

The consequences of a portacaval shunt on liver function were studied in male Sprague-Dawley rats. Fourteen days after an end-to-side portacaval anastomosis the galactose elimination capacity and the plasma clearance of indocyanine green were reduced in proportion to the approximately 50% loss in liver mass. The biliary transport maximum for sulfobromophthalein, on the other hand, decreased by almost 70% from 153 to 52 nmoles per min per min per 100 g after portacaval anastomosis. This reduction of sulfobromophthalein excretion was accompained by a significant decrease in the hepatic conjugation of the dye to glutathione. Our findings demonstrate that a quantitative and qualitative functional deterioration of previously normal livers results from portal blood deprivation.

Animals↗

A new look at the plasma disappearance of sulfobromophthalein (BSP): correlation with the BSP transport maximum and the hepatic plasma flow in man.

In order to improve the clinical usefulness of the plasma disappearance curve of sulfobromophthalein (BSP), its components were analyzed in 26 control subjects, in 28 patients with cirrhosis, and in 13 cases of miscellaneous liver abnormalities. The uncorrected initial disappearance rate (ki) was found to discriminate best between the control and the patient groups. The second exponential component (k2) was linearly correlated with the transport maximum (Tm) on a double logarithmic plot, but appeared to be independent of the estimated hepatic plasma flow (EHPF). An interpretation of this relationship was possible, when based on a model having saturation kinetics for biliary excretion. The first exponential component (ki) appeared primarily determined by hepatic perfusion. These relationships may contribute to a better understanding and more rational use of dye excretion tests as measures of hepatic function. The data also add to our knowledge about the nature of the excretory defect in cirrhosis.

Adult↗

Inhibition of bile formation by high doses of taurocholate in the perfused rat liver.

Sodium taurocholate was administered to the in situ perfused liver of male Sprague Dawley rats at various rates below (57 and 114 nmol/min -g liver) and above (228 and 456 nmol/min -g liver) its biliary transport maximum (Tm) to study its effect on bile formation. As expected, bile flow increased with increasing dose until maximal bile salt excretion was reached. By contrast, during taurocholate infusions exceeding the taurocholate-Tm, bile flow and bile salt excretion decreased. Under those conditions, a given bile salt excretion was associated with a smaller volume of bile. A relationship between these effects and the concentration of taurocholate in the perfusate (160 to 860 nmol/ml) was suggested by the observation that bile formation returned toward normal when the taurocholate concentration was lowered by exchange of the perfusate.

Animals↗

Prostaglandin-induced choleresis in the rat.

It could be demonstrated that intraportal infusion of prostaglandin A1 (1 mug/min/100 g body wt.) in Wistar rats significantly increases bile flow. An analysis of the relationship between bile salt excretion and bile flow revealed that this choleresis is due to an increase in the bile salt independent fraction of bile.

Animals↗

[Diagnostic significance of serum bile acids].

The concentrations of bile acids in serum determined by a relatively simple enzymatic method ranged between 1.6 and 9.2 mumol/l in 60 normal volunteers and between 2.1 and 7.7. mumol/l in 14 patients with Gilbert's syndrome. In contrast, 48 patients with various liver diseases had - with 2 exceptions - markedly elevated serum bile acids (up to 140 mumol/l). Together with BSP retention, BSP disappearance and SGOT, the bile acid level in serum represented one of the most sensitive indices for detection of liver disease. The sensitivity of this test can be further increased by bile acid determination 2 h after a meal. Since this test is both simple and harmless its broader clinical use appears attractive.

Adolescent↗

[Conjugation of chenodeoxycholic acid and cholic acid during passage through liver].

Both chenodeoxycholic acid, in the dosage administered for dissolution of gallstones, and cholic acid are completely conjugated during one passage through the liver. The glycine:taurine ratio increases with the cumulative amount of exogenous bile acids secreted, which suggests consumption of available taurine. Since conjugation with glycine compensates for deficiency of the taurine conjugating system, it can be assumed that in the normal liver and with doses not exceeding 2.5 mmoles, chenodeoxycholic acid is efficiently and completely transformed into its "physiologic" conjugated form.

Bile Acids and Salts↗

[Slow infusion cholangiography in patients with jaundice].

Thirty patients with jaundice and serum bilirubins above 4 mg.% were examined by slow infusion cholangiography (40 ml. (20 g.) Ioglycamid in 500 ml. 0.9% NaC1 in ten hours). Diagnostic results were achieved in 38%; in 15 patients with extra-hepatic obstruction, the success rate was 13%, whereas in disease of the liver parenchyma, the success rate was 60%.

Adult↗

Prolonged drip-infusion cholangiography.

Previous experimenttal work in animals has shown that the hpatic excretion of iodipamide and ioglycamide is subject to a transport maximum (TM). Doses in excess of this TM are largely excreted in the urine. In the present study the TM for man was estimated in three subjects with indwelling T-tubes: figures of 19-23 mg/minute for ioglycamide were obtained. It was thought that prolonged administration of contrast at levels slightly above the TM might have advantages in patients with impaired liver function. In obstruction the gradual excretion of contrast could improve the chances of filling the ducts completely, while in hepato-cellular disease the gall bladder might have time to concentrate the contrast. Ioglycamide was therefore given by slow overnight infusion, equivalent to 35 mg/minute, to patients in whom standard cholangiography had been unsuccessful. The overall success rate was 75 per cent with similar improvement in obstructive and hepatocellular disease.

Adult↗