Drug-induced gastrointestinal disease.

Clinicians administering potent therapeutic agents must be aware of their side-effects. The gut is an important site of adverse drug reactions and drug-induced disease must always be considered in the differential diagnosis of patients presenting with gastrointestinal symptoms. A careful drug history must therefore be taken in all such patients. Symptoms can often be related to drug ingestion, but late effects also occur. The presence of blood in vomitus or stool is pathognomonic of serious pathology which may be drug-induced and requires further investigation. Upper gastrointestinal haemorrhage and pseudomembranous colitis are potentially fatal manifestations of drug therapy. Gastrointestinal symptoms can often be avoided if therapy is taken with meals or in a smaller dose, but drug withdrawal is always the first line of management in patients whose symptoms may be drug-induced.

Morphometric studies in duodenal biopsies from patients with coeliac disease: the effect of the steroid fluticasone propionate.

Morphometric measurements have been performed on small intestinal biopsy specimens from patients with untreated coeliac disease before and after six weeks oral treatment with a steroid of low systemic bioavailability (fluticasone propionate). Measurements were obtained by point counting and also by a computer-aided measuring system with reference to a constant area of the muscularis mucosa. Fluticasone propionate led to a parallel reduction in the intraepithelial lymphocyte count within the surface (P less than 0.001) and crypt epithelium (P less than 0.01). The intra-epithelial lymphocyte count assessed by reference to constant areas of the muscularis mucosa and surface epithelium were decreased two-fold (P less than 0.01) and seven-fold (P less than 0.001) respectively. Fluticasone propionate treatment also led to significant increases in the absorptive surface epithelium as shown by an increase in the villus:crypt ratio (P less than 0.01), the epithelial cell height (P less than 0.01) and two- to three-fold increases in the area and length of the surface epithelium (P less than 0.001). Short-term fluticasone propionate treatment appears to exert a powerful beneficial effect upon duodenal morphology in patients with coeliac disease. Whether the alterations seen are comparable to a similar period of gluten withdrawal is not yet known.

Review: the pharmacological control of variceal bleeding.

The haemodynamic effects and clinical uses of drugs used in the management of patients with oesophageal variceal bleeding are reviewed. Vasoconstrictor agents (vasopressin, teripressin) alone or in combination with nitrates continue to be used for acute bleeding episodes, while somatostatin is an alternative. Alpha- and beta-adrenergic blocking drugs and vasodilators which lead to a sustained decrease in portal pressure can be used for the prevention of bleeding episodes, but despite numerous studies the pharmacological treatment of variceal bleeding remains controversial.

Haemodynamic responses to 1.25 and 2 mg of terlipressin intravenously in man.

The systemic and hepatic haemodynamic effects following terlipressin (Glypressin) administration were studied. Bolus intravenous injections of 1.25 and 2 mg significantly decreased wedged hepatic vein pressure gradient by 29% and 31%, respectively. With each dose there was a small increase in mean arterial blood pressure but after 1.25 mg of terlipressin, estimated hepatic blood flow fell by only 11% (not significant) compared to 24% after 2 mg, while the cardiac index fell by 12% compared to 29%. The adverse haemodynamic effects of terlipressin were diminished by a decrease in dosage, without any alteration in the beneficial effect of the drug upon portal pressure. Whether the smaller dose will be effective in arresting variceal haemorrhage remains to be determined.

Is topical therapy necessary in acute distal colitis? Double-blind comparison of high-dose oral mesalazine versus steroid enemas in the treatment of active distal ulcerative colitis.

Thirty-seven patients suffering an attack of acute distal ulcerative colitis of mild or moderate severity were randomized in a double-blind, double-dummy fashion to receive either 800 mg oral mesalazine four times daily (18 patients) or steroid enemas twice daily (19 patients) for 4 weeks. Both treatments were well tolerated with no adverse effects. Three patients in each group were withdrawn because of clinical deterioration but both treatments produced significant clinical improvement with decreases in stool frequency and scores for urgency, bleeding and tenesmus. There were no significant differences between the treatments although there was a slight trend in favour of the enemas for reduction in rectal bleeding. Activity of the colitis as graded at sigmoidoscopy also decreased significantly with both treatments and there were corresponding improvements in histological parameters of inflammatory activity assessed with the aid of a computerized morphometric system. Little correlation was seen between clinical, sigmoidoscopic and histological changes.

Monitoring methotrexate-induced hepatic fibrosis in patients with psoriasis: are serial liver biopsies justified?

BACKGROUND: Reports that up to 26% of subjects with psoriasis develop cirrhosis have led to a recommendation of serial liver biopsies after each cumulative dose of 1500 mg of methotrexate. AIM: To evaluate the progression of liver injury in patients with psoriasis and the impact of monitoring by liver biopsy on their management. METHODS: One hundred and twenty-one liver biopsies from 66 subjects (aged 11-79 years) with psoriasis, receiving a median cumulative dose of 3206 mg of methotrexate over a period of 280.5 weeks, were evaluated. RESULTS: The assessment of advanced fibrosis according to the Ishak system (>or= 4) correlated perfectly with that of the Scheuer system (>or= 3) and poorly with that of the Roenigk scale (>or= 3b) (r2 = 1.0 and 0.31, respectively). Two of 24 pre-treatment biopsies showed advanced fibrosis and both subjects were heavy drinkers. The cumulative probabilities of advanced fibrosis (Ishak >or= 4) were 0%, 2.6%, 2.6%, 8.2% and 8.2% at cumulative doses of 1500, 3000, 4500, 5000 and 6000 mg, respectively. None of the subjects developed cirrhosis during follow-up or discontinued therapy on the basis of liver biopsy findings. CONCLUSIONS: Advanced hepatic fibrosis with low-dose methotrexate therapy is much less frequent than previously reported. Pre-treatment or monitoring liver biopsies in accordance with the current guidelines have little impact on patient management.

Quantitative assessment of gastric atrophy using the syntactic structure analysis.

AIM: To assess the topographical relation between gastric glands, using the minimum spanning tree (MST), to derive both a model of neighbourhood and quantitative representation of the tissue's architecture, to assess the characteristic features of gastric atrophy, and to assess the grades of gastric atrophy. METHODS: Haematoxylin and eosin stained sections from corporal and antral biopsy specimens (n = 139) from normal patients and from patients with nonatrophic gastritis and atrophic gastritis of grades 1, 2, and 3 (Sydney system) were assessed by image analysis system (Prodit 5.2) and 11 syntactic structure features were derived. These included both line and connectivity features. RESULTS: Syntactic structure analysis was correlated with the semiquantitative grading system of gastric atrophy. The study showed significant reductions in the number of points and the length of MST in both body and antrum. The standard deviation of the length of MST was significantly increased in all grades of atrophy. The connectivity to two glands was the highest and most affected by the increased grade of atrophy. The reciprocal values of the Wiener, Randic, and Balaban indices showed significant changes in the volume of gland, abnormality in the shape of glands, and changes in irregularity and branching of the glands in both types of gastric mucosa. There was a complete separation in the MST, connectivity, and index values between low grade and high grade gastric atrophy. CONCLUSIONS: (1) Gastric atrophy was characterised by loss of the gland, variation in the volume, reduction in the neighbourhood, irregularity in spacing, and abnormality in the shape of the glands. (2) Syntactic structure analysis significantly differentiated minor changes in gastric gland (low grade atrophy) from high grade atrophy of clinical significance. (3) Syntactic structure analysis is a simple, fast, and highly reproducible technique and appears a promising method for quantitative assessment of atrophy.

Antitoxin production in antibiotic-associated colitis?

The production of antitoxin after Clostridium difficile-induced diarrhoea has not been reported previously. The stool of a patient with prolonged antibiotic-associated diarrhoea contained C. difficile toxin, and the serum neutralised the cytopathic effect of C. difficile toxin in tissue culture.

Quantitative assessment of fibrosis and steatosis in liver biopsies from patients with chronic hepatitis C.

BACKGROUND: Hepatic fibrosis is one of the main consequences of liver disease. Both fibrosis and steatosis may be seen in some patients with chronic hepatitis C and alcoholic liver disease (ALD). AIMS: To quantitate fibrosis and steatosis by stereological and morphometric techniques in patients with chronic hepatitis C and compare the results with a control group of patients with ALD. In addition, to correlate the quantitative features of fibrosis with the Ishak modified histological score. MATERIALS AND METHODS: Needle liver biopsies from 86 patients with chronic hepatitis C and from 32 patients with alcoholic liver disease (disease controls) were analysed by stereological and morphometric analyses using the Prodit 5.2 system. Haematoxylin and eosin and Picro-Mallory stained sections were used. The area fractions (A(A)) of fibrosis, steatosis, parenchyma, and other structures (bile duct and central vein areas) were assessed by stereological method. The mean diameters of fat globules were determined by morphometric analysis. RESULTS: Significant differences were found in the A(A) of fibrosis, including fibrosis within portal tract areas, between chronic hepatitis C patients and those with ALD (mean (SD): 19.14 (10.59) v 15.97 (12.51)). Portal and periportal (zone 1) fibrosis was significantly higher (p = 0.00004) in patients with chronic hepatitis C compared with the control group (mean (SD): 9.04 (6.37) v 3.59 (3.16)). Pericentral fibrosis (zone 3) occurred in both groups but was significantly more pronounced in patients with ALD. These results correlate well with the modified Ishak scoring system. However, in patients with cirrhosis (stage 6) with chronic hepatitis C the A(A) of fibrosis varied between 20% and 74%. The diameter of fat globules was significantly lower in patients with hepatitis C (p = 0.00002) than the ALD group (mean (SD): 14.44 (3.45) v 18.4 (3.32)). Microglobules were more frequent in patients with chronic hepatitis C than in patients with ALD. In patients with chronic hepatitis C, the fat globules had a zonal distribution in comparison with pan steatosis in ALD. CONCLUSION: Quantitative, stereological techniques are simple and reliable for evaluating hepatic fibrosis and steatosis in chronic hepatitis C. They are most useful for assessing the origin, location, and the stage of fibrosis. Stereology and morphometry are recommended for the quantitation of fibrosis and steatosis, particularly for the evaluation of new treatment strategies in patients with chronic hepatitis C.

Disturbances of lactate metabolism in patients with liver damage due to paracetamol overdose.

Six patients with liver damage following paracetamol overdose, one patient with viral hepatitis and six control subjects were infused with sodium L(+) lactate. In controls the results were analysed using a single compartment model while in paracetamol patients a two compartment system was used to derive the fractional rate removal constant and lactate distribution volume. Forearm arterio-venous differences of lactate were also determined in order to assess the role of voluntary muscle in removal of a lactate load. In paracetamol patients with fractional rate removal constant was decreased to less than half the control value (P less than 0.001) while total distribution volume was similar to the two groups. Fasting lactate concentrations were significantly increased in paracetamol patients due to diminished lactate removal since the endogenous production rate of lactate was not significantly different from controls. A greater proportion of the lactate load was removed in voluntary muscle in paracetamol patients (39%) than controls (17%). Since the balance of lactate removal occurs principally in the liver, the decrease in the fractional rate removal constant in patients following paracetamol overdose indicates a severe derangement of hepatic lactate metabolism with a compensatory increase in lactate metabolism in voluntary muscle.

Effect of acute inhibition of lipolysis on operation of the glucose-fatty acid cycle in hepatic cirrhosis.

Hepatic cirrhosis is frequently associated with glucose intolerance and insulin resistance, but the mechanisms underlying the insulin insensitivity are unknown. Plasma concentrations of nonesterified fatty acids (NEFA) are typically elevated in cirrhosis, and the glucose-fatty acid cycle provides a mechanism by which fatty acids may play a role in regulating glucose metabolism. We have therefore investigated the effect of acute inhibition of lipolysis, using the nicotinic acid analogue, acipimox, in 10 male patients with cirrhosis. All subjects were studied in the postabsorptive state after a 10- to 12-hour fast and were given either acipimox 250 mg or a placebo orally 2 hours before a 75-g oral glucose tolerance test (OGTT) and an infusion of insulin (50 mU/kg/h) and glucose (6 mg/kg/min) (insulin sensitivity tests [IST]). The drug was taken in a double-blind crossover design for each test. During the 2 hours following acipimox, there were rapid decreases in plasma NEFA, glycerol, and 3-hydroxybutyrate, confirming inhibition of lipolysis, while there were significant decreases in glucose, insulin, and C-peptide (P less than .001) compared with patients receiving the placebo. Acipimox blunted the increase in glucose after oral glucose loading and decreased incremental glucose concentration (from 579 +/- 76 to 445 +/- 65 mmol/min/L, P less than .02) and incremental insulin concentration (from 13.4 +/- 2.5 to 9.0 +/- 1.4 U/min/L, P = .056) in the OGTT. Improvements in classification of glucose tolerance were seen in five subjects. During the IST, significant reductions occurred in steady-state blood glucose (to 8.8 +/- 1 mmol/L, P less than .02) and C-peptide (to 3.0 +/- 0.5 nmol/L, P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

A method of enhancing verocytotoxin production by Escherichia coli.

The number of verocytotoxin producing Escherichia coli (VTEC) present in the faeces during an infection may be very low, making their detection difficult. We report a method for enhancing toxin production by VTEC using mitomycin C as an inducing agent with the aim of improving the detection of VTEC. In pure culture, mitomycin C enhanced toxin production up to 100-fold. When applied to mixed faecal culture, toxin could be detected in mitomycin C treated samples when standard cultures were negative and when substantially fewer verocytotoxin-producing bacteria were present. Use of this method may aid in the detection of VTEC and is appropriate for use in the routine diagnostic laboratory.

An HPLC assay for sn-1,2-diacylglycerol.

A method for the analysis of 1,2-diacylglycerols in biological samples is presented. After tissue extraction and derivatisation with 3,5-dinitrobenzoyl chloride, samples are analysed by normal phase HPLC, using a 3.9 x 300 mm microPorasil column, and ultraviolet detection at 254 nm. The method gives quantitative recovery of 1,2-diacylglycerol, and is of sufficient sensitivity to allow quantitation of 1,2-diacylglycerol in human muscle needle biopsy specimens, from as little as 10 mg muscle. Human skeletal muscle from fasted control subjects was found to have a 1,2-diacylglycerol content of 455 +/- 78 nmol/g wet weight. The method is robust, giving intra- and inter-assay coefficients of variation of 2.9% and 5.9%, respectively, and should prove useful for the analysis of 1,2-diacylglycerol levels in human disease states, such as diabetes, in which no measurements of 1,2-diacylglycerol have yet been undertaken.

Monosaccharide composition of haptoglobin in liver diseases and alcohol abuse: large changes in glycosylation associated with alcoholic liver disease.

Liver damage through prolonged intake of high amounts of alcohol is a serious problem that affects many members of the population. The aim of this study was to investigate changes in the glycosylation of haptoglobin (Hp) resulting from alcoholic liver diseases. The monosaccharide composition was measured in Hp isolated from 48 healthy individuals, 15 alcohol abusers (AA); 25 patients with alcoholic liver disease, including those with alcoholic cirrhosis (ALD/AC), and 17 other patients with either chronic active hepatitis (AH) or primary biliary cirrhosis (BC). Fucose was elevated per mol of Hp in 70%, 44%, and 33% of the individuals in the ALD/AC, BC and AA groups, respectively. Fucose was not elevated in the AH group. N-acetylglucosamine was also elevated in the ALD/AC group. Expressing results per 3 mol of mannose suggested the presence of higher branching with increased fucose content in Hp from all the abnormal groups except the AH group. More structural information is required to develop the diagnostic potential of carbohydrate measurements of Hp in alcoholic liver diseases.

Thermal desorption-gas chromatography of plasma isovaleraldehyde in hepatic encephalopathy in man.

The validation of a new assay for the leucine degradion product isovaleraldehyde in biological fluids is described. A gas purge technique was used with trapping of volatile constituents in a Tenax cartridge followed by automated thermal desorption and gas chromatographic analysis. The concentration of isovaleraldehyde during the course of hepatic encephalopathy (80 observations in 48 patients; 25 cirrhotic, 23 fulminant hepatic failure) was significantly increased compared to control subjects (0.58 +/- 0.08 compared to 0.17 +/- 0.02 mol/l; p less than 0.001). However, concentrations in grades 3-4 coma (37 observations) and grades 1-2 coma (30 observations) were similar and were not significantly different from values when encephalopathy was absent (grade 0; 13 observations). These results do not support an important role for isovaleraldehyde in the pathogenesis of hepatic encephalopathy.

Effect of methionine loading and endogenous hypermethioninaemia on blood mercaptans in man.

In five patients with cirrhosis given an oral methionine load, blood mercaptan concentrations were not significantly affected by neomycin and metronidazole therapy. Methanethiol and dimethyl sulphide rose after methionine to levels encountered in hepatic encephalopathy but in stable cirrhotics no neurological abnormalities were evident. In one patient with chronic hepatic encephalopathy there was no significant change in methanethiol, dimethyl sulphide or ammonia concentration 4 h after methionine when conscious state had deteriorated by two stages of encephalopathy. Elevations in blood methanethiol and dimethyl sulphide concentration in children with congenital hypermethioninaemia were not associated with any neurological or electroencephalographic features of hepatic coma. These studies do not support an important role for mercaptans in hepatic encephalopathy although a synergistic effect cannot be excluded. Furthermore, mercaptans appear to arise from endogenous metabolism rather than bacterial action in the gut.

Therapeutic modalities in portal hypertension.

Optimal medical management is with octreotide or terlipressin (Glypressin) for acute variceal bleeding and combined beta-blocker and nitrate prophylaxis for prevention of rebleeding. Injection sclerotherapy is necessary to arrest acute bleeding, with variceal banding preferred for the obliteration of large varices. Transjugular intrahepatic portosystemic shunts (TIPS) are best used for uncontrolled or recurrent bleeding episodes which fail to respond to endoscopic or drug therapy. They can also rarely be used to treat refractory ascites. Surgical portosystemic shunting and devascularization techniques have now been superseded. Hepatic transplantation should be considered where overall hepatic function is poor.

Transjugular intrahepatic portosystemic shunt: a limited role in refractory ascites.

OBJECTIVE: To evaluate the role of the transjugular intrahepatic portosystemic shunt (TIPS) in the management of patients with refractory ascites. DESIGN: A retrospective study of 25 consecutive patients for whom refractory ascites was the primary indication for TIPS insertion. SETTING: Regional liver unit at Freeman Hospital, Newcastle upon Tyne, UK. PARTICIPANTS AND INTERVENTIONS: Twelve male and 13 female patients with a mean age of 58 years and mean Child-Pugh score of 10, treated with TIPS for refractory ascites between July 1992 and September 1995. MAIN OUTCOME MEASURES: Effect of TIPS on mortality, ascites and hospital admission rate. RESULTS: TIPS was successfully placed in all patients with a 59% mean reduction in portosystemic pressure gradient. Response rate was 68%, 48% and 33% at 1, 3 and 12 months, respectively. Mortality was 48% at 3 months and 67% at 12 months, being higher in those patients older than 60, those with renal impairment and those with higher Child-Pugh score. Amongst nine patients surviving long term (> 12 months) the mean time spent in hospital in the 3 months before TIPS was 35 days and in the year following TIPS 30 days. Patients who died (16 in total) spent a mean of 19 days in hospital before TIPS, 10 never leaving hospital, and 6 who were discharged spent a mean of 19 days post procedure in hospital (mean survival 84 days). CONCLUSION: TIPS has a limited role in the management of patients with refractory ascites. It is not an appropriate treatment where patients are older than 60, have renal impairment (creatinine > 200 mumol/l) or have a Child-Pugh score greater than 10.

Incidence and causes of rectal bleeding in general practice as detected by colonoscopy.

BACKGROUND: Rectal bleeding is common, but it is still unclear which patients require investigation to exclude serious pathology, although it is known that colectoral cancer is very rare under the age of 40 years. Few studies have examined all patients presenting to their primary health physician rather than screening whole populations. AIM: The aim of this study was to investigate the view that all patients over the age of 40 who present to their general practitioner with rectal bleeding should undergo investigation by colonoscopy to rule out serious pathology, regardless of symptomatology. METHOD: A prospective study was carried out of 99 consecutive patients over 40 years presenting with rectal bleeding to 17 general practices in Newcastle upon Tyne. RESULTS: Serious pathology was detected by colonoscopy in 44.4% of patients. The diagnoses were: colorectal carcinoma, eight cases (two Dukes' grade A, two Dukes' grade B, four Dukes' grade C); one or more polyps, 25 cases (in 17 cases at least one polyp was 5 mm or greater in diameter); inflammatory bowel disease, 11 cases. In the remaining 55 patients, bleeding was associated with diverticular disease (16 cases) and haemorrhoids (28 cases). No cause was found in 11 patients. This high rate of pathology may be partly caused by selection of cases for referral by the general practitioner, despite efforts to minimize this. Three symptoms as elicited by the colonoscopist were found to be significantly associated with serious disease: blood mixed with stool (P < 0.001); change in bowel habit (P < 0.005); and the presence of abdominal pain (P < 0.025). However, symptoms elicited on primary presentation were less helpful and symptoms changed significantly between consultation with the general practitioner and colonoscopy. CONCLUSION: All patients over the age of 40 years presenting with rectal bleeding should be referred for flexible sigmoidoscopy or colonoscopy. Symptoms are unhelpful in deciding who requires investigation.

Plasmapheresis in acute liver failure.

A series of 9 patients with acute hepatic failure and Grade IV hepatic coma received daily plasmapheresis until they recovered or death ensued. Of the nine, seven (77%) showed an improvement in coma grade and five (55%) survived to leave hospital. Plasmapheresis significantly decreased serum bilirubin, aspartate aminotransferase and plasma ammonia concentrations. Survival following plasmapheresis appeared substantially better than in a non randomized group of similar patients not plasmapheresed. The simplicity of the procedure, biochemical improvements observed and apparent efficacy, suggest that further evaluation of the technique as a means of providing temporary hepatic support is indicated.