The effect of secretin on sodium ion absorption by the isolated human gallbladder.

Sodium ion (Na+) transport, a principal function of the gallbladder epithelium, was studied by measuring the flux of 22Na across isolated human gallbladder mucosa maintained in a modified 'Ussing' flux chamber. Tissue was obtained from cholecystectomy specimens in symptomatic patients with cholelithiasis. Out of 26 gallbladders studied, 13 had a net Na+ flux from mucosa to serosa which indicated active Na+ absorption. The hormone secretin, when added to the serosal fluid, reversed the direction of net flux in these gallbladders and caused a secretion of Na+ from serosa to mucosa. These results suggest that secretin may be involved in the physiological regulation of fluid transport in the human gallbladder, and also suggest a possible role for this hormone in gallbladder emptying.

Effect of propranolol on prevention of first variceal bleed and survival in patients with chronic liver disease.

BACKGROUND: Propranolol has been shown to be effective in both primary and secondary treatment of variceal haemorrhage; most primary prevention trials have only included patients with large oesophageal varices. AIM OF THE STUDY: The aim of this study was to look at the effect of propranolol in the primary prevention of variceal bleeding and its long-term effects on mortality in unselected patients with chronic liver disease. METHODOLOGY: Three hundred and nineteen patients were included in a double-blind parallel group study in three centres to receive propranolol 160 mg long-acting (LA) or placebo. Patients were followed up for a minimum of one year. RESULTS: There were eleven episodes of variceal bleeding and 38 deaths with no statistically significant difference in bleeding rates between the two treatment groups. Child's group and history of ascites were the most important prognostic factors determining the likelihood of early death and variceal bleeding respectively. CONCLUSIONS: In this study we failed to demonstrate a significant effect of propranolol on first variceal bleeding or in prolonging survival in unselected patients with chronic liver disease. Our results, however, might have been influenced by the low event rate observed in these unselected group of patients and suggest that careful selection of patients who are most likely to benefit from propranolol is important.

A comparison between gastric and oesophageal variceal haemorrhage treated with transjugular intrahepatic portosystemic stent shunt (TIPSS).

BACKGROUND: Transjugular intrahepatic portosystemic stent-shunts (TIPSS) are becoming widely used in the management of oesophageal variceal haemorrhage (OVH). Their place in the treatment of gastric variceal haemorrhage (GVH), a condition with a traditionally poor prognosis, remains unclear. The aims of our study were to compare portal haemodynamics and patient outcome in patients undergoing TIPSS for either GVH or OVH. PATIENTS AND METHODS: 106 consecutive patients undergoing TIPSS at our institution for either GVH (32 patients) or OVH (74 patients) were studied. The groups were similar with regard to patient age, aetiology and severity of liver disease and number of procedures carried out as an emergency (34.4% vs. 36.5%). Episodes of shunt insufficiency, rebleeding, encephalopathy and other clinical sequela were recorded. Mean follow-up was similar in both patient groups (14.2 vs. 12.1 months). RESULTS: Baseline portocaval pressure gradient was lower in patients with GVH compared with those with OVH (13.0+/-0.9 mmHg vs. 19.0+/-0.6 mmHg) (P < 0.001). Rates of variceal rebleeding, encephalopathy and shunt insufficiency during follow-up were similar in both groups and there was no difference in survival. CONCLUSION: Patients with GVH had markedly lower portocaval pressure gradients than those with OVH, but shunt and clinical complications and survival were similar during follow-up. TIPSS appears to be an effective treatment for GVH and should be compared with endoscopic or surgical techniques in controlled trials.

The formation of gallstones.

There are two types of gallstones; cholesterol and pigment or bilirubinate. Cholesterol stones are formed in the gallbladder as a consequence of altered hepatocellular and gallbladder function. Overproduction of cholesterol by the liver is the major metabolic precedent of cholesterol gallstones and this may occur because of obesity, drugs, or other factors. Gallbladder factors which promote stone formation include hypomotility and the secretion of nucleating factors such as mucus glycoprotein. It is possible that both of these two factors are mediated by an increase in the prostaglandin production by the gallbladder mucosa. Pigment stones are either brown or black. Brown stones are formed of calcium bilirubinate and are usually associated with biliary infection. They occur in both the gallbladder and the bile ducts. Black pigment stones are extremely hard bilirubin polymers and are found mainly in the gallbladder. Biliary sludge is a necessary precedent of gallstones. It comprises cholesterol monohydrate crystals, glycoproteins and granules of calcium bilirubinate.

Influence of the gallbladder on serum bile acids.

Serum bile acids (SBA) were studied after a standard fatty meal in patients with gallbladder disease. Early postprandial bile acid values were found to be greater in patients with non-functioning gallbladders. Higher postprandial SBA values were found after cholecystectomy. Serum bile acid measurements were of no value in the assessment of gallbladder function.

A comparative trial of liver biopsy needles.

A sheathed needle (Tru-Cut) was compared with a suction biopsy needle (Menghini) in a randomised prospective trial over 18 months to determine whether the former offered any special advantages in routine percutaneous liver biopsy. Seventy-seven consecutive biopsies were performed by a single operator. Although biopsy fragmentation was commoner with the suction needle, the length and volume of the largest core obtained was similar to results with the sheathed needle. Cytology provided useful additional information with the Menghini technique. The suction needle was repeatedly reusable and considerably cheaper than the sheathed needle, which may be used once only.

Radioimmunoassay of primary bile salts in serum.

Rapid, sensitive radioimmunoassays have been developed for the conjugated primary bile salts, cholate and chenodeoxycholate, using immunogens prepared by the mixed anhydride procedure. Antibodies produced showed equal specificity for glycine and taurine conjugates. Cross-reactivities were comparable with those from other published radioimmunoassays. The assays were routinely performed on unextracted sera and the concentrations correlated well with concentrations determined by gas-liquid chromatography. Accuracy, determined by the addition of bile salt to charcoal-extracted serum, and percision, determined by replicate analysis of a normal sample, were both less than +/- 10%. These figures are comparable with those obtained by both gas-liquid chromatography and other radioimmunoassays for bile salts. Normal sera were found to contain 0.49-1.32 mumol/l of cholate and 0.55-2.02 mumol/l of chenodeoxycholate. Serum concentrations in patients with liver disease were higher than this normal range. Three patients with mild liver distrubance were found to have one bile salt in the upper limit of normal, but in each case the other primary bile salt was outwith the normal range.

Fluctuations of serum bile acid concentrations during the menstrual cycle.

Fasting primary bile acid conjugates were measured in 44 women by radioimmunoassay methods. Bile acid values were significantly greater in the 21 women who were in the first half of the menstrual cycle than in the 23 women in whom blood was sampled during the second half of the cycle. Similar measurements were made at weekly intervals after menstruation in five subjects; increased values were observed in the first week. It is concluded that serum bile acid values fluctuate during the menstrual cycle.

Evaluation of the Lundh test in the diagnosis of pancreatic disease.

The Lundh test meal was administered to 32 normal subjects and 53 patients with suspected pancreatic disease. Tryptic activity was measured in the recovered duodenal juice. The level of activity distinguished the normal subjects from those with independently confirmed pancreatic disease, particularly chronic pancreatitis and carcinoma of the pancreas. The advantages and disadvantages of the test are discussed.

Measurement of serum primary bile acid ratio by gas liquid chromatography and radioimmunoassay.

The application of a sensitive gas liquid chromatography (GLC) assay has enabled patients in different diagnostic groups to be differentiated on the basis of the ratio of the primary bile acids, cholic: chenodeoxycholic acid. Because this method is unsuitable for a routine clinical laboratory, the primary bile acid ratio (PBR) is determined by radioimmunoassay techniques (RIA), and the results were compared with GLC analysis. RIA provided comparable results in control subjects and patients with large-duct obstruction, but significantly higher PBR values were found in cirrhotic subjects.

Serum bile acids in patients with hyperlipidaemia.

Individual serum bile acids were analysed by an improved gas liquid chromatography method in 12 patients with primary hyperlipidaemia. Total serum bile acid concentrations were raised in 10 subjects. Ursodeoxycholic acid was found in all 12 patients. It was present in significantly greater concentrations, accounted for a greater proportion of the total serum bile acids, and occurred more frequently than in patients with various forms of hepatobiliary disease. Patients with hyperlipidaemia had proportionately less deoxycholic acid than controls but more than patients with liver disease. There was proportionately less chenodeoxycholic acid in patients with hypercholesterolaemia, in whom the primary bile acid ratio was raised.

Serological markers of hepatitis B in patients with alcoholic liver disease: a multi-centre survey.

In a study of 195 patients derived from five centres in northern Britain and with histologically confirmed alcoholic liver disease we have found an increased prevalence of serological markers of hepatitis B. This increased prevalence was found in each of the five centres; the overall frequency ranged from 11% sero-positivity in fatty liver, 12% in alcoholic hepatitis and 27% in cirrhosis.

Characteristics of cholesterol absorption by human gall bladder: relevance to cholesterolosis.

The characteristics of cholesterol uptake by 83 human gall bladders (obtained at cholecystectomy) were studied with a modified Ussing technique. Real and artificial biles labelled with 14C-cholesterol and 3H-dextran (the latter to correct for adherent mucosal bile) were used; all gall bladders absorbed cholesterol (average 3.5 nmol/cm2/minute). Recovery of the absorbed cholesterol from the tissue showed that about 4% was esterified over 60 minutes. In artificial bile the rate of absorption of cholesterol increased as the bile saturation index rose, but became constant once supersaturation was achieved. In contrast, supersaturated real bile permitted greater absorption of cholesterol, possibly due to enhanced cholesterol solubilisation. Preincubation of gall bladder tissue in sodium cyanide (5 mM) caused a 30% reduction in cholesterol uptake indicating that, although absorption is predominantly a "passive" process, there is a partial "active" component. There were no pronounced differences in the rate of cholesterol absorption as gall bladders became more diseased, but there was a reduction in the amount of cholesterol ester formed.

125I Radioimmunoassay of serum ursodeoxycholyl conjugates.

A radioimmunoassay for serum ursodeoxycholic conjugates using a 125iodine ligand has been developed. The bile acid was present in normal fasting serum (0.19 +/- SD 0.19 mumol/l, n = 24) and 2-hour post-prandial serum (0.8 +/- SD 0.8 mumol/l, n = 16). Gallstone patients undergoing oral ursodeoxycholic acid therapy had significantly higher post-prandial serum levels (21.5 +/- SD 14.0 mumol/l, n = 15) by radioimmunoassay. Gas liquid chromatography analysis indicated that in normal serum ursodeoxycholic acid was totally conjugated, whereas sera from gallstone patients contained a proportion as the free bile acid (10.2 +/- SD 8.1 mumol/l, n = 15). Following an oral dose of ursodeoxycholic acid, both unconjugated and conjugated forms of the bile acid appeared in the serum of healthy individuals.

The estimation of phospholipids in bile.

Total and lipid phosphorus were measured in the duodenal aspirate of 24 fasting subjects following an injection of cholecystokinin. The lipid phosphorus values were lower than the total phosphorus, a difference most pronounced in dilute samples. Storage at -20 degrees C over 4 weeks resulted in a loss of over 50% lipid phosphorus. Such alterations in the lipid phosphorus affected the calculation of biliary phospholipid and hence the saturation index of cholesterol in bile causing it to be erroneously elevated. It is concluded that analysis of bile samples should be undertaken on freshly obtained samples and include a preliminary step for the extraction of lipids.

Plasma glutathione S-transferase measurements in patients with alcoholic cirrhosis.

Hepatocellular damage has been assessed in 54 patients with biopsy proven alcoholic cirrhosis by measuring the activity of aspartate aminotransferase (AST) and the concentrations of glutathione S-transferase B1B1 (GST B1B1) and B2B2 (GST B2B2) in serum. The levels of AST, GST B1B1, or GST B2B2 were abnormal in 28, 28 and 17 patients respectively but abnormalities in AST and GST measurements appeared to identify different populations of patients.

Glutathione S-transferase in human bile.

Glutathione S-transferase (GST) isoenzymes have been measured by specific radioimmunoassay in human bile samples. GST Mu was found in 50% of samples while GST Pi, GST B1 and GST B2 were present in all samples; GST Pi constituted the major isoenzyme identified. The findings of the radioimmunoassay were confirmed by a one-step purification of GST from bile, using affinity chromatography, followed by their identification using sodium dodecyl sulphate-polyacrylamide gel (SDS-PAGE). Inhibition studies showed that, at the concentrations of bile salts found in bile, GST Pi would have little or no enzymic activity. It is proposed that GST Pi acts as a carrier protein of toxic, non-substrate, ligands to remove as yet unidentified substances from biliary epithelial cells and prevent their reabsorption.

Cholesteryl esters in human gallbladder bile and mucosa.

Cholesteryl esters, identified by thin-layer and gas-liquid chromatography followed by mass spectroscopy in a few cases, were found in all human bile samples analysed. The amount varied extensively both in absolute concentration and when expressed as a percentage of the total cholesterol present. In about 30% of samples, the percentage of ester exceeded 4% of total cholesterol but there was no clear association with the presence of cholesterol gallstones or pigment stones, nor was there any association with the lithogenicity of bile.

Glutathione S-transferase levels in autoimmune chronic active hepatitis: a more sensitive index of hepatocellular damage than aspartate transaminase.

Glutathione S-transferase (GST; EC 2.5.1.18), a sensitive marker of hepatocellular damage, was measured in patients on therapy for histologically proven, autoimmune chronic active hepatitis at various stages of the disease. GST levels were elevated in 65% of serum samples despite immuno-suppressive treatment compared with aspartate transaminase (AST) which was increased in only 23% of samples. In 55% of samples with normal AST concentrations, GST was elevated. No samples demonstrated abnormal transaminase with normal GST levels. It is concluded that continuing hepatocellular damage occurs in patients with autoimmune chronic active hepatitis on immuno-suppressive treatment.

Pharmacokinetics of enalapril and lisinopril in subjects with normal and impaired hepatic function.

The pharmacokinetic and pharmacodynamic profiles of two angiotensin-converting enzyme (ACE) inhibitors, enalapril (a prodrug) and lisinopril (directly acting), were compared in eight patients with hepatic cirrhosis and 10 healthy controls. The pharmacokinetics of both drugs were affected in patients with hepatic cirrhosis. The percentage urinary recovery of the parent (inactive) drug enalapril was higher in patients with cirrhosis than controls. Serum concentrations of both drugs showed considerable variation in cirrhotic patients, but the variance ratio between patients with cirrhosis and controls was greater for enalapril than lisinopril. Peak serum concentrations of both ACE inhibitors were higher in patients with cirrhosis than in controls, which may be due to increased drug absorption. The time to peak drug concentration was longer for lisinopril than enalapril.