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M J Langman

Publications and source records attributed to M J Langman.

At least 19 recordsLinked to original sources
PubMed2001

Heparin therapy for ulcerative colitis? Effects and mechanisms.

Despite intensive medical treatment with steroids and immunosuppressants, acute colitis is still associated with a colectomy rate of up to 15%. Following the observation that a patient with severe steroid-resistant colitis went into remission when treated with heparin for a deep vein thrombosis, there have been a number of reports on the use of heparin in acute ulcerative colitis. Although small and uncontrolled, these studies consistently demonstrate the beneficial effects of heparin, with surprisingly few side-effects in a disease characterized by mucosal haemorrhage. The mechanisms by which heparin may ameliorate ulcerative colitis remain unclear. A simple anticoagulant effect may be responsible, but similar effects are not seen with warfarin. As a result of their intense negative charge, the glycosaminoglycans that constitute heparin have diverse biological effects. These include potent anti-inflammatory actions, in vitro and in vivo, and the potentiation of the activity of the peptide growth factors necessary for mucosal regeneration and repair. This review summarizes the clinical reports on heparin treatment for ulcerative colitis and explores the mechanisms by which this novel form of treatment may exert its effects.

Adjuvants, Immunologic↗
PubMed2001

Which PPI?

Explore the source record for details and available documents.

Anti-Ulcer Agents↗
PubMed2000

Effect of anti-inflammatory drugs on overall risk of common cancer: case-control study in general practice research database.

OBJECTIVE: To examine whether anti-inflammatory drug treatment protects against the commoner cancers in the United Kingdom. DESIGN: Case-control study using the general practice research database. SETTING: Practices throughout United Kingdom providing data to the database. SUBJECTS: Patients who had a first diagnosis of five gastrointestinal (oesophagus, stomach, colon, rectum, and pancreas) cancers and four non-gastrointestinal (bladder, breast, lung, and prostate) cancers in 1993-5 for whom prescription data were available for the at least the previous 36 months. Each case was matched for age, sex, and general practice with three controls. MAIN OUTCOME MEASURE: Risk of cancer. RESULTS: In 12 174 cancer cases and 34 934 controls overall risk of the nine cancers was not significantly reduced among those who had received at least seven prescriptions in the 13-36 months before cancer diagnosis (odds ratio 0.98, 95% confidence interval 0.89 to 1.07). Findings were nevertheless compatible with protective effects from anti-inflammatory drugs against cancers of the oesophagus (0.64, 0. 41 to 0.98), stomach (0.51, 0.33 to 0.79), colon (0.76, 0.58 to 1. 00), and rectum (0.75, 0.49 to 1.14) with dose related trends. The risk of pancreatic cancer (1.49, 1.02 to 2.18) and prostatic cancer (1.33, 1.07 to1.64) was increased among patients who had received at least seven prescriptions, but the trend was dose related for only pancreatic cancer. CONCLUSIONS: Anti-inflammatory drugs may protect against oesophageal and gastric cancer as well as colon and rectal cancer. The increased risks of pancreatic and prostatic cancer could be due to chance or to undetected biases and warrant further investigation.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2000

Drug treatment of non-variceal upper gastrointestinal bleeding.

Despite many clinical investigations, proof is lacking that pharmacological treatments significantly influence the outcome in non-variceal upper gastrointestinal bleeding. Reaching conclusions has been hindered by the small size of many studies in a situation in which a large number of patients must be included if confident conclusions are to be reached. In addition, many studies, by comparing two potentially active treatments without a placebo group, have been unable to determine whether an equivalence of the active treatments represents equivalent but active or equivalent but inactive therapy.

Diagnosis, Differential↗
PubMed2000

Oestrogen inactivation in the colon: analysis of the expression and regulation of 17beta-hydroxysteroid dehydrogenase isozymes in normal colon and colonic cancer.

Epidemiological data suggest that oestrogen contributes to the aetiology of colonic cancer. Furthermore, recent studies have suggested that local hormone metabolism may play a key role in determining colonic responsiveness to oestrogen. To further clarify this mechanism we have characterized the expression and regulation of isozymes of 17beta-hydroxysteroid dehydrogenase (17beta-HSD) in vitro and in situ. Immunohistochemistry was used to confirm expression of the type 2 and 4 isozymes of 17beta-HSD (17beta-HSD2 and 4) in normal colonic epithelial cells. Parallel studies suggested that both isozymes were abnormally expressed in colonic tumours and this was confirmed by Western blot analyses. Abnormal expression of 17beta-HSD2 and 4 proteins was also observed in Caco-2, HT-29 and SW620 colonic cancer cell lines, although the overall pattern of oestrogen metabolism in these cells was similar to that seen in primary colonic mucosal tissue. The predominant activity (conversion of oestradiol to oestrone) was highest in Caco-2>SW620>HT-29, which correlated inversely with the rate of proliferation of the cell lines. Regulatory studies using SW620 cells indicated that the most potent stimulator of oestradiol to oestrone inactivation was the antiproliferative agent 1,25-dihydroxyvitamin D3 (1,25D3), whilst oestradiol itself inhibited 17beta-HSD activity. Both oestradiol and 1,25D3 decreased mRNA for 17beta-HSD2 and 4. Data indicate that the high capacity for inactivation of oestrogens in the colon is associated with the presence of 17beta-HSD2 and 4 in epithelial cells. Abnormal expression of both isozymes in colonic cancer cells and the stimulation of oestrogen inactivation by the antiproliferative agent 1,25D3 highlights a possible role for 17beta-HSD isozymes as modulators of colonic cell proliferation.

17-Hydroxysteroid Dehydrogenases↗
PubMed2000

Peptic ulcer bleeding: accessory risk factors and interactions with non-steroidal anti-inflammatory drugs.

AIMS: To determine risk factors for peptic ulcer bleeding other than non-steroidal anti-inflammatory drugs (NSAIDs). Methods-Data on possible antecedent risk factors obtained in a large case control study of 1121 patients admitted to hospitals in Glasgow, Newcastle, Nottingham, Oxford, and Portsmouth with bleeding peptic ulcers were compared with the same information obtained in 989 population controls. Data were analysed by logistic regression with the calculation of odds ratios (OR) and 95% confidence intervals (CI). RESULTS: From a logistic regression model, oral anticoagulants (OR 7. 8; 95% CI 2.8-21.5), previous peptic ulcer (3.8; 2.6-4.9), treatment for heart failure (5.9; 2.3-13.1), oral corticosteroid use (2.7; 1. 3-4.5), treatment for diabetes (3.1; 1.2-4.3), and current smoking (1.6; 1.2-2.0) were all independent risk factors. No association was found with use of calcium channel antagonists. Odds ratios for concomitant NSAID usage were multiplicative with the exception of current smoking. CONCLUSIONS: Some 45% of admissions for peptic ulcer bleeding in England and Wales in those aged 60 or more are calculated to be attributable to, or associated with, these accessory risk factors, which, together with those associated with aspirin or other NSAID use will account for over 80% of predisposing factors to ulcer bleeding.

Aged↗
PubMed1999

Adverse upper gastrointestinal effects of rofecoxib compared with NSAIDs.

CONTEXT: Nonsteroidal anti-inflammatory drug (NSAID)-induced gastrointestinal (GI) toxic effects, such as upper GI tract perforations, symptomatic gastroduodenal ulcers, and upper GI tract bleeding (PUBs), are thought to be attributable to cyclooxygenase 1 (COX-1) inhibition. Rofecoxib specifically inhibits COX-2 and has demonstrated a low potential for causing upper GI injury. OBJECTIVE: To compare the incidence of PUBs in patients with osteoarthritis treated with rofecoxib vs NSAIDs. DESIGN: Prespecified analysis of all 8 double-blind, randomized phase 2b/3 rofecoxib osteoarthritis trials conducted from December 1996 through March 1998, including one 6-week dose-ranging study, two 6-week efficacy studies vs ibuprofen and placebo, two 1-year efficacy studies vs diclofenac, two 6-month endoscopy studies vs ibuprofen and placebo, and one 6-week efficacy study vs nabumetone and placebo. SETTING: Multinational sites. Participants Osteoarthritis patients (N = 5435; mean age, 63 years [range, 38-94 years]; 72.9% women). INTERVENTIONS: Rofecoxib, 12.5, 25, or 50 mg/d (n = 1209, 1603, and 545, respectively, combined) vs ibuprofen, 800 mg 3 times per day (n = 847), diclofenac, 50 mg 3 times per day (n = 590); or nabumetone, 1500 mg/d (n = 127) (combined). MAIN OUTCOME MEASURE: Cumulative incidence of PUBs for rofecoxib vs NSAIDs, based on survival analysis of time to first PUB diagnosis, using PUBs that met pre-specified criteria judged by a blinded, external adjudication committee. RESULTS: The incidence of PUBs over 12 months was significantly lower with rofecoxib vs NSAIDs (12-month cumulative incidence, 1.3% vs 1.8%; P = .046; rate per 100 patient-years, 1.33 vs 2.60; relative risk, 0.51; 95% confidence interval, 0.26-1.00). The cumulative incidence of dyspeptic GI adverse experiences was also lower with rofecoxib vs NSAIDS over 6 months (23.5% vs 25.5%; P = .02), after which the incidence rates converged. CONCLUSION: In a combined analysis of 8 trials of patients with osteoarthritis, treatment with rofecoxib was associated with a significantly lower incidence of PUBs than treatment with NSAIDs.

Adult↗
PubMed1999

Risks of anti-inflammatory drug-associated damage.

Non-steroidal anti-inflammatory drug toxicity to the upper gastrointestinal tract differs consistently and strongly between the individual agents. Exact measures of the difference are not yet available because meta-analyses combining individual data sets from a sufficiently large number of subjects and incorporating dosage information are not available. The importance of obtaining such information is emphasised by simple modelling based upon expected usage patterns and disease risks. The adverse effects of the non-steroidal anti-inflammatory drugs (NSAIDs) are, in terms of general population impact, the most common and important of all adverse effects of pharmaceuticals in any group. This is because they are widely used, and the adverse effects are common. Amongst these adverse effects, gastrointestinal problems, manifested by peptic ulceration and its complications, are by far the most frequent. Approaches to prevention can be of three general types. The first is the characterisation and mitigation of the circumstances under which the effects occur, the second the use of preventative treatments, and the third the introduction of selective agents by which therapeutic properties are retained and adverse effects minimised. This commentary concentrates on characterising the extent of risks. However, a good understanding will not be achieved without knowledge of the general epidemiology of peptic ulceration.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1999

Prospective, double-blind, placebo-controlled randomized trial of cimetidine in gastric cancer. British Stomach Cancer Group.

Cimetidine is thought to inhibit suppressor T-lymphocyte function and preliminary evidence from a randomized trial indicated that it might prolong survival for patients with operable and inoperable gastric cancer. The British Stomach Cancer Group conducted a randomized, double-blind, placebo-controlled trial examining the effects of cimetidine (400 mg or 800 mg twice a day) on the survival of patients with early (stages I, II and III: n = 229) and advanced (stages IVa and IVb: n = 201) gastric cancer. The primary end point was death. A total of 442 patients were randomized by 59 consultants in 39 hospitals between February 1990 and March 1995. Log-rank survival analysis was used to assess differences between the groups. Three hundred and forty patients died during the study: 166 (49%) in the cimetidine treatment groups and 174 (51%) in the placebo groups. Median survival for patients receiving cimetidine was 13 months (95% confidence interval (CI) 9-16 months) and 11 months in the placebo arm (95% CI 9-14 months). There was no significant difference in survival between the two treatment groups (P = 0.42) or between different doses of cimetidine tablets (P = 0.46). Five-year survival of those patients randomized to cimetidine was 21% compared to 18% for those patients randomized to placebo. Cimetidine at a dose of 400 mg or 800 mg twice a day does not have a significant influence on the survival of patients with gastric cancer compared to placebo.

Adult↗
PubMed1999

Loss of estrogen inactivation in colonic cancer.

Age and sex differences in the incidence of colonic cancer, together with epidemiological data on patients taking hormone replacement therapy, suggest the involvement of estrogens. Analogous to the role of aromatase in breast cancer, we postulated that steroid metabolism within the colon itself may be a crucial mechanism in regulating tissue exposure to estrogens. We have characterized expression of aromatase (responsible for converting C19 androgens to C18 estrogens) and 17beta-hydroxysteroid dehydrogenase (17beta-HSD) [responsible for interconversion of active estradiol (E2) to less potent estrone (E1)] in normal and neoplastic human colon from 24 patients undergoing tumor resection. Aromatase activity was similar in homogenates from normal mucosa, tissue adjacent to tumors, and the tumors themselves. Analysis of 17beta-HSD activity indicated that the predominant activity was oxidative (E2 to E1), and this conversion was significantly lower in colonic tumors [444 (90-1735); median (95% confidence interval) pmol/mg protein x h], compared with normal mucosa [1709 (415-13828), P < 0.001]. Northern blot analyses indicated expression of messenger RNAs (mRNAs) for the type 2 and 4 isozymes of 17beta-HSD in normal colon; messenger RNA for 17beta-HSD 4 was significantly lower in tumor tissue [0.75 +/- 0.22 (mean +/- SD) arbitrary U vs. 0.43 +/- 0.17, P < 0.01]. Studies in vitro, using three colonic cancer cell lines, indicated that there was an inverse correlation between 17beta-HSD oxidative activity and the rate of cell proliferation. In addition, E1, but not E2, was shown to significantly decrease proliferation when added exogenously to the colonic epithelial cell line, SW620 cells. Colonic mucosa can regulate estrogen hormone action in an intracrine fashion. The loss of estrogen inactivation may be an important mechanism in the pathogenesis of colonic cancer.

17-Hydroxysteroid Dehydrogenases↗
PubMed1999

Epidemiology of non-steroidal anti-inflammatory drug damage to stomach and duodenum.

Conventional non steroidal anti-inflammatory drugs (NSAIDs) are probably responsible for a fifth to a quarter of cases of peptic ulcer bleeding, and for the same proportion of deaths. Predisposing factors include age, due probably to underlying susceptibility to ulcer, drug dosage, and the nature of NSAID. It is also likely that prior ulcer predisposes, but whether Helicobacter pylori infection without ulcer does so is unclear. Factors underlying the proportion of ulcer complications not associated causally with NSAID or aspirin treatment, two-third of cases, are largely unknown.

Age Distribution↗
PubMed1998

Expression of oestrogen receptor and oestrogen-inducible genes pS2 and ERD5 in large bowel mucosa and cancer.

Since there is a preponderance of large bowel cancer in males, both in humans and in experimental models, and hormone replacement therapy is protective, a role for sex steroid hormones in the pathogenesis of this neoplasm seems likely. Evidence of functional oestrogen receptor has been looked for in large bowel mucosa and cancer. Expression of oestrogen receptor, and of the oestrogen-inducible receptor-associated genes pS2 and ERD5, was sought. Oestrogen receptor mRNA was detected in cancers and paired normal mucosae in equal amounts. In situ hybridization identified stromal cells above the muscularis mucosae that were positive for oestrogen receptor mRNA. pS2 mRNA was also detected, with a signal intensity significantly higher in normal mucosa compared with cancers, whereas the reverse was seen with ERD5 mRNA levels. pS2 and ERD5 were expressed in epithelium, with the former in a greater amount in distal colon and rectum than proximal colon. Although oestrogen-inducible and receptor-associated genes are expressed in large bowel mucosa, their expression does not correlate with oestrogen receptor.

Aged↗
PubMed1998

Postmarketing surveillance of the safety of cimetidine: 15-year mortality report.

The pattern of mortality after 15 years of observation is reported among almost 10,000 patients who were taking cimetidine when they were first recruited between 1977 and 1980. Many took the drug for a number of years, some switching to other antisecretory agents as the study progressed. The findings are reassuring and provide no evidence of any long-term adverse effects of cimetidine which might be detected by monitoring mortality rates. The data have also been used to examine the possible positive relationships between aluminium ingestion and Alzheimer's disease and H. pylori infection and ischaemic heart disease. No significant evidence was obtained in support of the existence of these relationships.

Journal Article↗
PubMed1998

European network for the case-population surveillance of rare diseases (Euronet). A prospective feasibility study.

OBJECTIVE: Euronet, a case-population surveillance scheme, aims to estimate the risk of certain rare conditions which are commonly iatrogenic, by comparing drug use amongst non-selective cases with overall drug use in the general population. METHODS: The method is based on three provisos: (1) all incident cases (irrespective of suspected aetiology) should be ascertained and studied; (2) a full drug history should be obtained from cases by direct interview; and (3) drug-use data for the products of interest should be available for this population from which cases are chosen. The feasibility of this problem-oriented approach for the identification of new signals of adverse drug reactions and for risk estimation will be tested in relation to agranulocytosis, Stevens-Johnson syndrome and toxic epidermal necrolysis in four defined areas in Europe, totalling 19 x 10(6) inhabitants, with these latest two outcomes being studied in only three regions. The design, methods and main limitations of this case-population surveillance approach are described.

Adverse Drug Reaction Reporting Systems↗
PubMed1998

Inhibition of phenolsulphotransferase by salicylic acid: a possible mechanism by which aspirin may reduce carcinogenesis.

BACKGROUND: Recent epidemiological evidence has shown that chronic use of aspirin decreases susceptibility to bowel cancer. Animal studies have shown that sulphotransferase inhibitors coadministered with sulphation activated carcinogens dramatically reduce the incidence of cancer. AIMS: To investigate the effect of the main aspirin breakdown product, salicylic acid, on the P and M isoforms of phenolsulphotransferase from human platelets and colonic mucosa. METHODS: Platelets were obtained from healthy blood donors and isolated within 24 hours after donation. Samples of colonic mucosa were obtained at resection for non-malignant disease. Phenolsulphotransferase activity was measured in cellular homogenates using a standard radiolabelling assay. RESULTS: Salicylic acid consistently and selectively inhibited the P form of phenolsulphotransferase at subtherapeutic concentrations in both tissue samples. A 50% inhibition of sulphation by the P phenolsulphotransferase occurred at salicylic acid concentrations of about 40 and 130 microM in platelets and bowel mucosa respectively. M phenolsulphotransferase was virtually unaffected by salicylic acid up to a concentration of 1.5 mM (the therapeutic plasma concentration for salicylates when treating rheumatoid arthritis is about 1-2 mM). CONCLUSION: The action of salicylic acid on P phenolsulphotransferase, by preventing the excessive activation of carcinogens, is a possible additional pathway by which aspirin can reduce cancer risk.

Aged↗