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Biomedical subjects

R Raedsch

Publications and source records attributed to R Raedsch.

At least 73 records · Page 4Linked to original sources

Absorption of urso- and chenodeoxycholic acid and their taurine and glycine conjugates in rat jejunum, ileum, and colon.

Chenodeoxycholic acid (cheno) and ursodeoxycholic acid (urso) dissolve cholesterol gallstones in man. Comparative studies of the absorption of cheno and urso are not available. The absorption of urso and cheno and their glycine and taurine conjugates in jejunum, terminal ileum, and colon of the rat were therefore determined in an open in situ perfusion system. Absorption of unconjugated urso and cheno in jejunum, ileum, and colon was similar. In the jejunum conjugated urso and cheno were absorbed only in minimal amounts. In the ileum glycine-conjugated urso was absorbed to a lower extent than glycine-conjugated cheno (6.5 +/- 0.4 vs. 8.6 +/- 0.6 nmol/cm X h at 25 mumol/l bile acid concentration, p less than 0.05) and taurine-conjugated urso was absorbed less than taurine-conjugated cheno (6.4 +/- 0.5 vs. 8.1 +/- 0.7 nmol/cm X h, p less than 0.05). In the colon glycourso and taurourso were not absorbed, while glycocheno and taurocheno were absorbed in small amounts. The low reabsorption rates of urso conjugates in ileum and colon may contribute to the relatively low urso content in bile during urso treatment.

Animals↗

Stimulation of chemically induced rectal carcinogenesis by chronic ethanol ingestion.

The effect of chronic ethanol administration on 1, 2-dimethylhydrazine-induced rectal carcinogenesis was investigated in 32 paired male Sprague-Dawley rats fed a nutritionally-adequate liquid diet containing 36% of the total calories as either ethanol or isocaloric carbohydrates. Chronic ethanol ingestion increased the total number of rectal tumors significantly (17 vs 6; P less than 0.02), whereas no cocarcinogenic effect of ethanol was observed in other parts of the intestine. Alcohol did not influence tumor size or histopathology. A 47% increase in the activity of mucosal alcohol dehydrogenase in the distal colorectal region was found between chronically-ethanol-fed rats and pair-fed controls (0.241 +/- 0.019 vs 0.164 +/- 0.020 mumol/mg of protein/hr; P less than 0.01). This could in part explain the cocarcinogenic effect of alcohol in this tissue. Faecal bile acids, however, do not play a role as promotors of rectal carcinogenesis under the present experimental conditions. The results give experimental support to the epidemiologic findings of an increased incidence of rectal cancer in the alcoholic.

Adenocarcinoma↗

Absorption of 7-ketolithocholic acid in rat jejunum, ileum and colon.

7-Ketolithocholic acid is a bile acid which is formed in the intestine of man by bacterial oxidation of chenodeoxycholic acid and ursodeoxycholic acid. In contrast to deoxycholic acid and lithocholic acid 7-ketolithocholic acid after its intestinal absorption may be reduced in the liver to chenodeoxycholic acid or ursodeoxycholic acid. In the present study absorption of 7-ketolithocholic acid in jejunum, ileum, and colon was measured. When 7-ketolithocholic acid was perfused with a concentration of 0.025 mmol/l the absorption in the jejunum was 6.2 +/- 0.9 nmol/cmxh (mean +/- SD), in the ileum 8.1 +/- 0.2 nmol/cmxh, and in the colon 11.2 +/- 1.7 nmol/cmxh. The absorption of 7-ketolithocholic acid in jejunum, ileum, and colon was equal to the absorption of ursodeoxycholic and chenodeoxycholic acid. The equal absorption rates of 7-ketolithocholic, ursodeoxycholic, and chenodeoxycholic acid indicate, that substitution of the 7-hydroxyl group by the 7-keto group has no influence on the intestinal absorption of bile acids. The excellent colonic absorption of 7-ketolithocholic acid demonstrates, that not only the small intestine but also the colon contributes to the enterohepatic circulation of bile acids.

Animals↗

Enhancement of 1,2-dimethylhydrazine-induced rectal carcinogenesis following chronic ethanol consumption in the rat.

The incidence, distribution, size, and histopathology of grossly visible intestinal tumors induced by the parenteral administration of 1,2-dimethylhydrazine dihydrochloride were examined in 32 paired rats fed a nutritionally adequate liquid diet containing 36% of total calories either as ethanol or isocaloric carbohydrates. The liquid diets were begun 4 wk before the first of four weekly injections of 1,2-dimethylhydrazine dihydrochloride. At the time of the subcutaneous application of the procarcinogen, liquid diets were omitted for 3 wk, and were replaced by a standard laboratory diet. This feeding schedule was repeated four times, and after 32 wk the animals were killed. Chronic ethanol ingestion increased the total number of rectal tumors significantly (17 vs. 6, p less than 0.02). However, alcohol had no effect on tumor size or histopathology. Chronic ethanol ingestion did not exhibit any cocarcinogenic effect in tissues other than the rectum. A 47% increase in the activity of mucosal alcohol dehydrogenase in the distal colorectum was found between chronically ethanol-fed rats and pair-fed controls (0.241 +/- 0.019 vs. 0.164 +/- 0.020 mumol X mg protein-1 X h-1, p less than 0.01). This could in part explain the cocarcinogenic effect of alcohol in this tissue. Fecal bile acids, however, do not play a role as promoters of rectal cancer under the present experimental conditions. The data give experimental support to the epidemiologic findings of an increased incidence of rectal cancer in the alcoholic.

Adenocarcinoma↗

Hepatic secretion of bilirubin and biliary lipids in patients with alcoholic cirrhosis of the liver.

In patients with cirrhosis of the liver elevated bilirubin concentrations in the plasma could be the result of decreased bilirubin excretion or an overproduction of bilirubin with insufficient excretion of the increased amounts of bilirubin. Under steady state conditions with constant serum bilirubin concentrations bilirubin synthesis equals biliary and urinary bilirubin excretion. In the present study in 10 healthy volunteers and 11 patients with alcoholic cirrhosis of the liver and serum bilirubin concentrations of 7.0 +/- 1.9 mg/dl the biliary excretion of bilirubin was studied by the intestinal perfusion method and compared with the excretion of bile lipids. Biliary excretion of bilirubin in the cirrhotics was 38.7 +/- 8.8 mumol/h, the 10 healthy controls excreted 17.9 +/- 0.9 mumol/h bilirubin. Only minor amounts of bilirubin were excreted in urine. In 4 of the 11 cirrhotics 51Cr-red blood cell half-lives were studied revealing ongoing hemolysis. Bilirubin production calculated from red cell life span was identical to biliary excretion of bilirubin with an error less than 5%. The data indicate that in patients with alcoholic cirrhosis of the liver serum concentrations of bilirubin may be elevated due to overproduction of bilirubin and a concomitant decrease of the biliary transport capacity of bilirubin.

Adult↗

Biliary excretion of procollagen type III peptide in healthy humans and in patients with alcoholic cirrhosis of the liver.

Serum concentrations of procollagen type III peptide are found to be elevated in liver disease and to correlate with fibrosis activity in liver tissue. These elevated serum levels may be due to enhanced synthesis, decreased excretion, or release from deposits of the propeptide in connective tissue. To quantitatively investigate the excretion of procollagen type III peptide, we studied its presence in the bile and urine of 10 healthy controls and 11 patients with alcoholic cirrhosis of the liver. Biliary excretion rates of procollagen propeptide were determined by the duodenal perfusion method. The serum concentrations of procollagen type III peptide were 2.5 +/- 0.5 ng/ml in the healthy controls and 33.6 +/- 6.8 ng/ml in the patients with cirrhosis. Procollagen type III peptide was found in the bile; the healthy controls excreted 0.4 +/- 0.07 nmol/h and the cirrhotics excreted 0.98 +/- 0.27 nmol/h. A fragment of the procollagen propeptide, Col 1, was excreted in urine; the healthy controls excreted 0.25 +/- 0.04 nmol/h, and the cirrhotics excreted 0.11 +/- 0.03 nmol/h. These data demonstrate that the biliary excretion of procollagen type III peptide represents a quantitatively important pathway.

Bile↗

[Comparative treatment of gastroduodenal haemorrhage with secretin and cimetidine].

In a prospective multicenter study 71 patients with acute, non-arterial gastroduodenal haemorrhage from ulcers or stress lesions were treated alternately with synthetic secretin (Hoe 0690 (n = 35) or with cimetidine (n = 36). Both medications were given by infusion over 48 hours. Prior to commencement of treatment the haemorrhage was verified gastroscopically. During infusion of secretin cessation of hemorrhage was achieved without recurrence in 30 out of the 35 patients within the 48-hour infusion time and in 3 patients with recurrence within the same period. Two patients failed to obtain discontinuation of haemorrhage within the infusion period. Cimetidine led to cessation of haemorrhage without recurrence within 48 hours in 20 out of 3 patients, 3 patients had recurrences. Haemorrhages could not be arrested in 13 patients within the two-day treatment period. Differences between success of treatment among the two groups are significant (P less than 0.01) favouring secretin.

Adult↗

Analysis of bile acid glucuronides in urine: group separation on a lipophilic anion exchanger.

A chromatographic separation of glucuronidated bile acids using the anion exchanger diethylaminohydroxypropyl Sephadex LH-20 (DEAP LH-20) is described. Group separation of non-sulfated, non-glucuronidated bile acids, bile acid glucuronides, bile acid monosulfates, and bile acid disulfates was obtained. The method allowed analysis of all these bile acid derivatives in the urine of 15 patients with cirrhosis of the liver and cholestasis. The patients excreted in mean 30.4 mumol/24 h non-sulfated, non-glucuronidated bile acids, 90.3 mumol bile acid monosulfates, and 10.2 mumol bile acid glucuronides. Glycine- or taurine-conjugated were 68% of the non-sulfated, non-glucuronidated bile acids, 96% of bile acid sulfates, and 81% of bile acid glucuronides.

Bile Acids and Salts↗

Oral keto analogs of branched-chain amino acids in hyperammonemia in patients with cirrhosis of the liver. A double-blind crossover study.

Previous uncontrolled studies indicated a positive effect of keto analogs of amino acids on plasma ammonia in patients with cirrhosis of the liver and on portal-systemic encephalopathy. In the present double-blind study the influence of keto analogs of the branched chain amino acids valine, leucine and isoleucine on plasma ammonia and encephalopathy was investigated in 12 patients with cirrhosis of the liver and surgical portal systemic shunts. In addition to the usual therapy with lactulose and protein restriction (40 g protein/day) all patients received 15.24 g keto analogs and placebo orally over 4 weeks in a crossover regimen. In contrast to uncontrolled studies, plasma ammonia, which was elevated in all patients before the beginning of the study, was not significantly changed. In addition plasma amino acids, electroencephalogram, number connection test, clinical state and laboratory tests were not influenced by the therapy with keto analogs.

Administration, Oral↗

Procollagen-type III-peptide serum concentrations in chronic persistent and chronic active hepatitis and in cirrhosis of the liver and their diagnostic value.

Until now the determination of fibrotic processes in liver disease was restricted to histological examination of liver tissue. Recently a RIA was developed to determine the procollagen-type III-peptide concentrations in biological fluids. We used this RIA to measure the serum procollagen-type III-peptide concentrations in patients with chronic liver disease. Additionally in 24 patients with chronic persistent and chronic active hepatitis the collagen content in liver biopsies was determined histomorphometrically. The serum procollagen-type III-peptide concentrations in healthy controls (n = 40) were 6.4 +/- 0.6 ng/ml, in chronic persistent hepatitis (n = 47) 8.7 +/- 0.5 ng/ml, in chronic active hepatitis (n = 53) 20.8 +/- 2.9 ng/ml, and in alcoholic cirrhosis of the liver (n = 22) 47.7 +/- 6.1 ng/ml. Thus the patients with chronic active hepatitis and cirrhosis of the liver showed significantly elevated serum procollagen-type III-peptide levels. In chronic hepatitis a highly significant correlation (p less than 0.001) could be demonstrated between collagen content in liver tissue and serum procollagen-type III-peptide concentrations. The determination of serum procollagen-type III-peptide concentrations may prove a new useful parameter in biochemical evaluation of liver disease.

Biopsy↗

Altered bile acid metabolism in primary biliary cirrhosis.

Selected aspects of bile acid metabolism were assessed in six women with primary biliary cirrhosis and varying degrees of cholestasis. Urinary bile acid excretion was markedly increased and correlated highly with serum levels. In three patients in whom urinary bile acids were separated by chromatography, the majority of urinary bile acids were monosulfated (34%, 42%, 32%) or polysulfated and/or glucuronidated (30%, 20%, 38%). The monosulfates of chenodeoxycholic acid were conjugated at either the 3 position (67%, 68%, 73%) or the 7 position (33%, 32%, 27%); similarly, the monosulfates of cholic acid were conjugated at the 3 position (65%, 58%, 68%) or the 7 position (35%, 42%, 32%). The position of sulfation was not markedly influenced by the mode of amidation with glycine or taurine. Chenodeoxycholic exchangeable pool size, turnover rate, and synthesis were measured by isotope dilution and found to be well within normal limits, despite the cholestasis. The fraction of chenodeoxycholic acid synthesis excreted in urine ranged from 9 to 48%; 4--38% of chenodeoxycholic acid synthesis was sulfated. These data indicate that the major abnormalities in bile acid metabolism in patients with cholestasis secondary to primary biliary cirrhosis are formation of sulfated bile acids in greatly increased amounts, elevation of blood levels of primary bile acids, and a shift to renal excretion as a major mechanism for bile acid elimination. Chenodeoxycholic acid synthesis continues at its usual rate despite cholestasis. Whether these changes, including the formation of 7-monosulfated bile acids, occur in other forms of cholestasis and whether either the persistance of unchanged chenodeoxycholic acid synthesis or the formation of such novel conjugates has any pathophysiological significance remain to be investigated.

Adult↗

Kinetics of cholesterol gallstone dissolution by glycocheno-, glyco-ursodeoxycholic acid, and mixtures of both in vitro.

Cheno- and ursodeoxycholic acid feeding are both efficient in conservative gallstone therapy. Urso decreases biliary cholesterol excretion even more than cheno. Glyco-urso becomes dose dependent the predominant bile acid conjugate in bile under urso feeding. We therefore studied the kinetics of cholesterol gallstone dissolution in aqueous solutions of 100 mM glyco-cheno, 100 mM glyco-urso, and mixtures of both consisting of 40 mM glyco-urso plus 60 mM glyco-cheno and 80 mM glyco-urso plus 20 mM glyco-cheno in vitro. The daily dissolution rates of cholesterol achieved by these solutions were for 100 mM glyco-cheno 0.87 +/- 0.1 mg (mean +/- SEM), for 40 mM glyco-urso plus 60 mM glyco-cheno 0.28 +/- 0.003 mg, for 80 mM glyco-urso plus 20 mM glyco-cheno 0.07 +/- 0.002 mg, and for 100 mM glyco-urso 0.07 +/- 0.03 mg. Correspondingly were the weight decreases of the gallstones by 100 mM glyco-cheno 1.2 +/- 0.1 mg/day, by 40 mM glyco-urso plus 60 mM glyco-cheno 0.3 +/- 0.01 mg/day, by 80 mM glyco-urso plus 20 mM glyco-cheno 0.11 +/- 0.02 mg/day, and by 100 mM glyco-urso 0.1 +/- 0.02 mg/day. Complete gallstone dissolution occurred during the observation time of 4 months only by 100 mM glyco-cheno in 12.8 +/- 3.3 weeks. Thus glyco-urso dissolves only little cholesterol and decreases the speed of cholesterol gallstone dissolution. It is concluded that high doses of urso in gallstone therapy which lead to great amounts of glyco-urso in bile may diminish gallstone dissolution rates.

Chenodeoxycholic Acid↗

Passage of a large bilirubin stone through a narrow papillotomy.

Large stones in the bile are generally considered to be a contraindication for endoscopic papillotomy (EPT). In the case described a large biliary stone passed spontaneously into the lumen of the gut after EPT. It is speculated that pure pigment stones are less "rigid" than cholesterol stones and are therefore able to pass through narrower channels than cholesterol stones.

Aged↗

Effects of biliary bile acid composition on biliary cholesterol saturation in gallstone patients treated with chenodeoxycholic acid and/or ursodeoxycholic acid.

Chenodeoxycholic acid (cheno) and ursodeoxycholic acid (urso) dissolve cholesterol gallstones in humans. In the present study conjugation of biliary bile acids with glycine and taurine and their effects on biliary cholesterol saturation were investigated during treatment with cheno, urso, and cheno-urso. Ten patients were included in this study, and every patient served as his own control. Each of the treatment periods lasted for 3 mo. During treatment with cheno or urso, daily doses of 11.9-15.6 mg/kg were administered, while during treatment with cheno-urso each bile acid was administered at one-half the dose. In the control period biliary bile acids consisted of 31.8 +/- 2.8% glycocheno, 10.9 +/- 1.2% taurocheno, 1.0 +/- 0.1% glycourso, and 0.3 +/- 0.1% taurourso. During the three treatment periods dihydroxy bile acids in bile and glycine conjugation of these dihydroxy bile acids increased significantly (P < 0.05). During treatment with urso the amounts of glycourso in bile were positively correlated to the dose of urso administered (P < 0.05). No correlation existed between urso dose and the amounts of taurourso in bile. Biliary cholesterol was 9.0 +/- 1.0 mol% in the control period and decreased during treatment with cheno, urso, and chenourso to 5.2 +/- 0.5, 3.7 +/- 0.3, and 3.8 +/- 0.3 mol%, respectively. Cholesterol saturation index corrected for the biliary content of glycourso and taurourso was 1.2 +/- 0.1 in the control period and decreased during treatment with cheno, urso, and cheno-urso to 0.8 +/- 0.1, 1.0 +/- 0.1 and 0.7 +/- 0.1, respectively. Thus urso treatment led to the lowest biliary content of cholesterol, but cheno-urso treatment led to significantly lower cholesterol saturation indices than urso treatment (P < 0.05).

Aged↗

Separation of individual sulfated bile acid conjugates as calcium complexes using reversed-phase partition thin-layer chromatography.

A method for separating individual monosulfated primary bile acid conjugates by reversed-phase partition thin-layer chromatography on octadecyl-bonded silica gel is described. The solvent system is acetonitrile containing calcium, probably as calcium carbamate. Excellent resolution of the 3- and 7-monosulfated glycine conjugates, as well as 3- and 7-monosulfated taurine conjugates of cholic and chenodeoxycholic acids is reported. A convenient class separation of sulfated from nonsulfated primary bile acid conjugates by adsorption thin-layer chromatography on low-polarity silica gel is also described.

Bile Acids and Salts↗

Pool size, synthesis, and turnover of sulfated and nonsulfated cholic acid and chenodeoxycholic acid in patients with cirrhosis of the liver.

In 5 patients with cirrhosis of the liver sulfated and nonsulfated [14C]cholic acid and [14C]chenodeoxycholic acid were administered intravenously and the specific activity curves were determined. Specific activities declined exponentially and pool sizes, synthesis rates, and turnover rates of bile acids were calculated on the basis of a one-pool system. The biological half-life of cholic acid was 4.3 +/- 1.6 days (mean +/- SEM) and of chenodeoxycholic acid was 2.8 +/- 1.2 days. The half-life of cholic acid sulfate was 0.7 +/- 0.5 day and of chenodeoxycholic acid sulfate was 0.8 +/- 0.5 day. The pool size of cholic acid was 513 +/- 103 mg, of chenodeoxycholic acid, 477 +/- 77 mg, of cholic acid sulfate, 4.7 +/- 1.0 mg, and of chenodeoxycholic acid sulfate, 38.7 +/- 4.0 mg. The daily synthesis of cholic acid was 90 +/- 14 mg, of chenodeoxycholic acid, 118 +/- 6 mg, of cholic acid sulfate, 7.2 +/- 2.1 mg, and of chenodeoxycholic acid sulfate was 32.6 +/- 3.2 mg. The data indicate that sulfate esters of bile acids are significantly more rapidly excreted than are unsulfated bile acids. More than one-fourth of the chenodeoxycholic acid but less than one-tenth of the cholic acid formed was sulfated. The preferential sulfation of chenodeoxycholic acid is responsible for the more rapid turnover of chenodeoxycholic acid in comparison to cholic acid. Sulfation enhances the excretion and thereby prevents the accumulation of hepatotoxic concentrations of chenodeoxycholic acid in patients with cirrhosis of the liver.

Alkaline Phosphatase↗