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Biomedical subjects

R J Playford

Publications and source records attributed to R J Playford.

At least 19 recordsLinked to original sources
PubMed2003

Current practice in surveillance strategy for patients with Barrett's oesophagus in the UK.

BACKGROUND: Many guidelines exist regarding the surveillance of patients with Barrett's oesophagus. There are limited data, however, with regard to whether practitioners follow these guidelines. METHODS: We assessed current surveillance practice amongst members of the British Society of Gastroenterology using a simple 11-question anonymous survey, mailed to 300 randomly selected members from the British Society of Gastroenterology Handbook. RESULTS: Two hundred and three of the 300 (68%) responded, 76% considering that surveillance was worthwhile. In those who considered surveillance to be worthwhile, 83% used sub-selection based on age, the length of Barrett's oesophagus or the presence of ulcer or stricture. Patients with Barrett's oesophagus of < 3 cm (short-segment) were considered to be inappropriate for surveillance by 62%. Forty-one per cent reported following the 'advised' recommendations of four-quadrant biopsies every 2 cm, whereas 44% followed a 'random and suspicious areas only' protocol. Marked variation was reported in the re-endoscope interval for both low- and high-grade dysplasia. Only 55% reported that two experienced pathologists reviewed all biopsies showing high-grade dysplasia. CONCLUSIONS: Despite the existence of multiple guidelines for Barrett's surveillance, clinical practice varies widely in the UK. This may be due to a lack of knowledge or because gastroenterologists remain unconvinced by the quality of the current evidence of its value. These results have implications for studies attempting to collate data from multiple centres.

Barrett Esophagus↗
PubMed2003

Effect of epidermal growth factor administration on intestinal cell proliferation, crypt fission and polyp formation in multiple intestinal neoplasia (Min) mice.

Recombinant epidermal growth factor (EGF) may be useful to treat severe ulcerative gastrointestinal injury. There is concern, however, that systemic use of this potent mitogen might increase tumour development and/or progression in susceptible subjects. We therefore examined the effect of chronic administration of systemic EGF to multiple intestinal neoplasia (Min ) mice, who have a genetic defect in the adenomatous polyposis coli (APC) gene, leading to increased polyp development. Min mice (n =26) and wild-type littermates (n =26) received saline or EGF (223 microg of EGF/kg per day) for 4 weeks using subcutaneous osmotic mini-pumps. Cell proliferation and crypt fission were analysed using microdissection techniques and the number and size of polyps in the small and large intestines were determined. EGF increased wet weight and crypt cell proliferation rate by approx. 20% (all P <0.01 compared with the relevant control) in the small intestine and colon of both control and Min mice. In both groups, EGF reduced the colonic fission index by approx. 40% (P <0.01), but did not affect crypt fission in the small intestine. In Min mice, administration of EGF did not increase numbers of polyps or degree of dysplasia, but resulted in a 40% increase in the polyp size in the proximal intestine (P <0.02), but not in the remainder of the small intestine or colon. No polyps were found in control mice given EGF. EGF did not initiate polyp formation in control or Min mice. However, as polyp size is an important determinant for subsequent risk of malignant change in human colon cancer, further studies appear justified.

Adenomatous Polyposis Coli↗
PubMed2002

Use of the 'nutriceutical', bovine colostrum, for the treatment of distal colitis: results from an initial study.

BACKGROUND: Bovine colostrum is a rich source of nutrients, antibodies and growth factors. AIM: To examine the efficacy of colostrum enemas in the treatment of distal colitis using a randomized, double-blind, controlled protocol. METHODS: Fourteen patients (eight female), with a mean age of 45 years (range, 16-75 years) and mild to moderately severe distal colitis (Powell-Tuck scoring system), received colostrum enema (100 mL of 10% solution) or placebo (albumin solution) b.d. for 4 weeks. Both groups also received mesalazine (1.6 g/day) or, if already taking it, had a dose increment of 1.6 g/day. Disease activity was documented at 0, 2 and 4 weeks. RESULTS: After 4 weeks, the colostrum group showed a mean reduction in symptom score of - 2.9 (95% confidence interval (CI), - 5.4 to - 0.3), whereas the placebo group showed a mean response of + 0.5 (95% CI, - 2.4 to +3.4). The histological score improved in five of the eight patients in the colostrum group (mean response, - 0.9; 95% CI, - 1.69 to - 0.03), whereas the histological scores only improved in two of the six patients in the placebo group (mean response, 0.2; 95% CI, - 2.4 to +2.6). CONCLUSIONS: Bovine colostrum enema shows potential as a novel therapy for left-sided colitis with additional benefits over using mesalazine alone. Further studies appear to be warranted.

Adolescent↗
PubMed2002

Does Helicobacter pylori eradication reduce the long-term requirements for acid suppressants in patients with a history of peptic ulcer disease in general practice? Results from a four-year longitudinal study.

BACKGROUND: Acid suppressants, especially proton-pump inhibitors, are major contributors to the drug costs in primary care. Although Helicobacter pylori eradication reduces peptic ulcer relapse, some studies suggest that patients may remain symptomatic and continue to require acid-suppressant therapy. METHODS: We identified all patients taking long-term acid suppressants in a large primary health care clinic to determine the proportion who had peptic ulcer disease and to examine the effect of H. pylori eradication on their long-term requirement for acid suppressants. RESULTS: 126/394 patients taking long-term acid suppressants had a definite diagnosis of peptic ulcer. Of these 126 patients, 60 were considered appropriate for the study. At Stage 1 (May 1994), all patients were tested for H. pylori infection and positive patients (60/66) received eradication therapy with omeprazole 20 mg bd and amoxycillin (1 gm bd) or clarithromycin (500 mg tds) for 2 weeks. Six weeks later (Stage 2) patients, requirements for continued acid-suppressant treatment were determined and previously positive subjects retested using the 13C urea breath rest. This showed that 70% (42/60) had been successfully eradicated. One year later (Stage 3), 44% (18/41) of the patients successfully eradicated still required acid suppressants. The majority of these patients (11/18; 61%) continued to remain on acid-suppressant treatment at 4 years (Stage 4) (95% CI 38%, 83%). CONCLUSIONS: We found that about 1/3 of all patients on long-term acid-suppressant therapy in General Practice had a confirmed diagnosis of peptic ulcer disease. Despite successful eradication treatment for H. pylori at the start of the study, about half of these patients still used acid suppressants after 1 year and 1/4 patients (11/41) in this group continued to remain on acid-suppressant treatment for another 3 years.

Amoxicillin↗
PubMed2002

Human transforming growth factor alpha (TGF-alpha) is digested to a smaller (1-43), less biologically active, form in acidic gastric juice.

BACKGROUND: Transforming growth factor alpha (TGF-alpha) is a 50 amino acid peptide with potent proliferative and cytoprotective activity present in gastric mucosa and juice. AIMS: To determine the forms and biological activity of natural and recombinant TGF-alpha following incubation with acid pepsin. PATIENTS: Human gastric juice was obtained under basal conditions from patients taking acid suppressants and from volunteers undergoing intragastric neutralisation. METHODS: Samples were analysed using mass spectroscopy and/or high pressure liquid chromatography with radioimmunoassay. Biological activity was determined using thymidine incorporation into rat hepatocytes and an indomethacin/restraint induced gastric damage rat model. RESULTS: TGF-alpha(1-50) is cleaved to TGF-alpha(1-43) by acid pepsin and this is the predominant form in normal gastric juice. However, intragastric neutralisation or taking acid suppressants caused the predominant form to be TGF-alpha(1-50). TGF-alpha(1-43) had only half of the ability to maximally stimulate [(3)H]thymidine incorporation into primary rat hepatocytes (28 177 (1130) DPM/well for 2.16 nM TGF-alpha(1-43) v 63 184 (3536) DPM/well for TGF-alpha(1-50); p<0.001). A similar reduced potency was seen when used in an indomethacin induced rat gastric damage model (0.18 micro mol/kg/h of TGF-alpha(1-43) reduced ulcer area by 19% whereas TGF-alpha(1-50) reduced area by 62%; p<0.001). CONCLUSIONS: TGF-alpha(1-50) is cleaved to the TGF-alpha(1-43) form by acid pepsin, causing 2-5-fold loss of biological activity. Such changes may have relevance to the actions of acid suppressants and the importance of this peptide in both normal and abnormal growth.

Animals↗
PubMed2002

Cost analysis of breath test versus endoscopy for dyspepsia.

BACKGROUND: There is currently much debate on the best way to manage dyspepsia in the community and cost effectiveness is often discussed. We aim to perform a cost analysis of a test and treat strategy for Helicobacter pylori versus endoscopy using data based on the breath test service in Leicester. METHODS: Retrospective analysis of data acquired over the 1-year period from March 1, 1999, to February 29, 2000, in a university teaching hospital. The main outcome measure was the cost of each management strategy. RESULTS: Referral to the breath test service cost pound 84.67 per person with dyspepsia (including treatment of positive patients and endoscopy cost of patients endoscoped). If the breath test service had not existed, referral for endoscopy would have cost pound 98.35 per person. This equates to a cost saving of pound 8,276 over the year studied for the 605 patients referred. It also resulted in 353 fewer endoscopies being performed. CONCLUSION: Direct referral to a H. pylori breath test service saves money, avoids an unpleasant test for many people and reduces the endoscopy waiting list.

Adult↗
PubMed2001

Effect of ectopic expression of rat trefoil factor family 3 (intestinal trefoil factor) in the jejunum of transgenic mice.

To further examine the function of the trefoil factor family (TFF), the expression of which is up-regulated at sites of injury, we have produced transgenic mice that chronically express rat TFF3 within the jejunum (using a rat fatty acid-binding protein promoter). The expression of rat TFF3 was limited to the villi of the jejunum and had no effect on base-line morphology. Rat TFF3 expression did result, however, in a reduced sensitivity to indomethacin (85 mg/kg subcutaneously), which only caused a 29% reduction in villus height in transgenics versus 51% reduction in controls (p < 0.01). Indomethacin increased initial intestinal epithelial cell proliferation and migration, but the presence of rat TFF3 caused no additional change in proliferation (bromodeoxyuridine), cell migration ([(3)H]thymidine and bromodeoxyuridine), apoptosis (terminal deoxyuridine nucleotidyl nick end labeling), or E-cadherin immunostaining. In vitro studies following changes in resistance of intestinal strips in Ussing chambers (voltage-clamp technique) showed increased base-line resistance in the rat TFF3-expressing region (326 +/- 60 versus 195 +/- 48 ohm.cm(2) in controls, p < 0.05) and reduced the fall in resistance following HCl exposure by about 40% (p < 0.01). Overexpression of TFF3 stabilizes the mucosa against noxious agents, supporting its role in mucosal protection/repair. It may therefore provide a novel approach to the prevention and/or treatment of intestinal ulceration.

Animals↗
PubMed2001

Epidermal growth factor reduces multiorgan failure induced by thioacetamide.

BACKGROUND: Multiorgan failure is a severe life threatening state where present therapeutic approaches are suboptimal. Epidermal growth factor (EGF) is a potent stimulant of repair in in vitro and in vivo models. We therefore examined its potential beneficial effect in reducing mortality and injury induced by the noxious agent thioacetamide (TAA). METHODS: Mice (20 per group) were fasted overnight and received a single intraperitoneal dose of human recombinant EGF at 10 or 30 microg/kg or saline (control). Either 30 minutes before or after EGF, all animals also received TAA (40 mg/kg intraperitoneally). Twenty four hours later, surviving animals were killed, tissues collected, and degree of organ injury assessed. RESULTS: Fifty per cent (10/20) of control animals died within the first 24 hour period. Mortality was almost completely prevented by the higher dose of EGF whether given before or after TAA (p<0.01) and was reduced by about 50% with the lower dose of EGF. In control animals, the entire length of the jejunum and ileum had necrosis with or without mucosal denudation. In contrast, necrosis affected only about 10-20% of the total length in EGF treated groups (both p<0.01 v control). Control animals showed marked glomerular tuft collapse, interstitial haemorrhage, and increased plasma creatinine levels. These effects were significantly reduced in animals given EGF (30 microg/kg; p<0.01). All groups showed similar changes in liver histology (centrilobular necrosis) and alanine transaminase levels (10-fold increase). CONCLUSIONS: Although EGF did not prevent the hepatotoxicity associated with TAA, it reduced mortality, renal injury, and gastrointestinal damage. These studies provide preliminary evidence that EGF may be a novel approach for the prevention and/or treatment of multiorgan failure.

Animals↗
PubMed2001

Gastrointestinal cell proliferation and crypt fission are separate but complementary means of increasing tissue mass following infusion of epidermal growth factor in rats.

BACKGROUND AND AIMS: Epidermal growth factor (EGF) is a potent mitogen for the gastrointestinal tract and also influences the number of new crypts formed by crypt fission. The time course of these events and possible linkage between these two complementary mechanisms is however poorly understood. We therefore examined the temporal relationship of proliferation and fission in rats treated with EGF. METHODS: Osmotic minipumps were implanted subcutaneously into male Wistar rats to infuse EGF continuously (60 microg/rat/day) for periods of 1-14 days. Proliferation and crypt branching were quantified following vincristine induced metaphase arrest and morphometric assessment of microdissected tissue. RESULTS: In the small intestine, EGF significantly increased epithelial cell proliferation and crypt and villus area after 24 hours of EGF, although maximal effects were only reached following six days of infusion. EGF also resulted in an approximate 30% reduction in crypt fission in the small bowel. In the colon, EGF caused a twofold increase in epithelial cell proliferation one day after infusion, from 15.3 (2.3) to 29.6 (3.5) metaphases per crypt (p<0.01). Maximal effects were seen in rats receiving EGF for seven days. For all time points, colonic crypt size increased in response to EGF. The amount of branching increased following one day of infusion with EGF (from 15.3 (1.9) to 32.4 (5.5)%; p<0.001) but was significantly lower (approximately 25% of control values) following longer periods of infusion. Crypt fission did not correlate with crypt area. CONCLUSION: EGF has profound effects on cell proliferation and also altered crypt fission, with its actions on crypt fission most pronounced in the colon where it first increased and then decreased fission. EGF can thus be a potent stimulus for crypt fission during short term infusion and may reduce the number of branched crypts present in a resting or quiescent stage. Growth factors can alter cell mass by two separate but linked mechanisms, namely altered cell production and crypt fission.

Animals↗
PubMed2001

Co-administration of the health food supplement, bovine colostrum, reduces the acute non-steroidal anti-inflammatory drug-induced increase in intestinal permeability.

Non-steroidal anti-inflammatory drugs (NSAIDs) are effective analgesics but cause gastrointestinal injury. Present prophylactic measures are suboptimal and novel therapies are required. Bovine colostrum is a cheap, readily available source of growth factors, which reduces gastrointestinal injury in rats and mice. We therefore examined whether spray-dried, defatted colostrum could reduce the rise in gut permeability (a non-invasive marker of intestinal injury) caused by NSAIDs in volunteers and patients taking NSAIDs for clinical reasons. Healthy male volunteers (n=7) participated in a randomized crossover trial comparing changes in gut permeability (lactulose/rhamnose ratios) before and after 5 days of 50 mg of indomethacin three times daily (tds) per oral with colostrum (125 ml, tds) or whey protein (control) co-administration. A second study examined the effect of colostral and control solutions (125 ml, tds for 7 days) on gut permeability in patients (n=15) taking a substantial, regular dose of an NSAID for clinical reasons. For both studies, there was a 2 week washout period between treatment arms. In volunteers, indomethacin caused a 3-fold increase in gut permeability in the control arm (lactulose/rhamnose ratio 0.36+/-0.07 prior to indomethacin and 1.17+/-0.25 on day 5, P<0.01), whereas no significant increase in permeability was seen when colostrum was co-administered. In patients taking long-term NSAID treatment, initial permeability ratios were low (0.13+/-0.02), despite continuing on the drug, and permeability was not influenced by co-administration of test solutions. These studies provide preliminary evidence that bovine colostrum, which is already currently available as an over-the-counter preparation, may provide a novel approach to the prevention of NSAID-induced gastrointestinal damage in humans.

Adult↗
PubMed2000

Final results from 10 year cohort of patients undergoing surveillance for Barrett's oesophagus: observational study.

OBJECTIVES: To review the benefit of an endoscopic surveillance programme for patients with Barrett's oesophagus. DESIGN: Observational study. SETTING: University teaching hospital. PARTICIPANTS: 409 patients in whom Barrett's oesophagus was identified during 1984-94; 143 were entered into the annual surveillance programme. MAIN OUTCOME MEASURES: Development of dysplasia and cancer and mortality. RESULTS: The average period of surveillance was 4.4 years; 55 patients were reassessed in 1994 but only eight remained in the programme in 1999, withdrawal being due to death (not from carcinoma of the oesophagus), illness, or frailty. Five of the patients who entered surveillance developed carcinoma of the oesophagus. Only one cancer was identified as a result of a surveillance endoscopy, the others being detected during endoscopy to investigate altered symptoms. Of the 266 patients who were not suitable for surveillance, one died from oesophageal cancer and 103 from other causes. Surveillance has resulted in 745 endoscopies and about 3000 biopsy specimens. CONCLUSION: The current surveillance strategy has limited value, and it may be appropriate to restrict surveillance to patients with additional risk factors such as stricture, ulcer, or long segment (>80 mm) Barrett's oesophagus.

Adolescent↗
PubMed2000

Does the response of the intestinal epithelium to keratinocyte growth factor vary according to the method of administration?

BACKGROUND: Keratinocyte growth factor (KGF) is a potent mitogen and may be of value for the treatment of conditions such as short bowel syndrome and chemotherapy-induced mucositis. However the most efficacious route and method of administration is unclear. METHODS: Rats maintained by total parenteral nutrition (TPN) were given KGF (1 mg/kg/rat/day, i.v.) infused continuously or as a once-daily injection. The same dose was also given s.c. to chow-fed rats. Changes in gut growth were assessed by measurement of wet weight, proliferation (vincristine induced metaphase arrest) and crypt branching index. Changes in gut hormone profile were also determined to examine if any trophic effects were mediated via this mechanism. RESULTS: KGF caused a 70-100% increase in wet weight of the stomach, small and large intestine of TPN-fed rats (P < 0.01) with no significant differences seen between the two methods of administration. The increase in metaphase counts was greatest in the stomach (about seven-fold P < 0.01), but was less pronounced in the distal small intestine and colon (about 50% increase). The trophic effect of KGF was much less prominent in orally-fed rats. Crypt branching index was significantly reduced by KGF in the proximal small intestine of TPN, but not orally-fed rats. Plasma gastrin, PYY, total glucagon, enteroglucagon and GLP-1 all increased by two-three-fold (all P < 0.01) in response to KGF whereas insulin levels fell by about 25% in the TPN group. CONCLUSIONS: The mitogenic action of KGF occurred predominantly in the stomach and proximal small intestine. Its efficacy was less pronounced in orally-fed animals, suggesting KGF may be of greatest benefit in conditions associated with lowered intestinal proliferation. Clinical trials of KGF can probably use single daily i.v. injections without reduction in efficacy.

Animals↗
PubMed2000

Colostrum and milk-derived peptide growth factors for the treatment of gastrointestinal disorders.

Colostrum is the specific first diet of mammalian neonates and is rich in immunoglobulins, antimicrobial peptides, and growth factors. In this article we review some of these constituents of human and bovine colostrum in comparison with those of mature milk. Recent studies suggest that colostral fractions, or individual peptides present in colostrum, might be useful for the treatment of a wide variety of gastrointestinal conditions, including inflammatory bowel disease, nonsteroidal antiinflammatory drug-induced gut injury, and chemotherapy-induced mucositis. We therefore discuss the therapeutic possibilities of using whole colostrum, or individual peptides present in colostrum, for the treatment of various gastrointestinal diseases and the relative merits of the 2 approaches.

Animals↗
PubMed2000

Potency and stability of C terminal truncated human epidermal growth factor.

INTRODUCTION: Epidermal growth factor (EGF) is normally present as EGF(1-53). A variety of C terminal truncated forms have been used in preliminary trials for treating gastrointestinal injury but their relative potency and stability when used in a clinical setting are unclear. Therefore, we compared the biological activity of recombinant EGF(1-53), EGF(1-52), EGF(1-51), and the C terminal peptides EGF(44-53) and EGF(49-53). METHODS: Purity of forms was confirmed by mass spectrometry. Bioactivity of the different EGF forms was determined using [methyl-(3)H] thymidine incorporation into primary rat hepatocytes and their ability to reduce indomethacin (20 mg/kg subcutaneously)/restraint induced gastric injury in rats. Stability of EGF peptides was determined by serial sampling from a syringe driver system containing EGF/4% albumin in saline. RESULTS: Biological activity assays of EGF(1-53), EGF(1-52), and EGF(1-51) gave almost identical thymidine uptake dose-response curves (maximal responses increasing baseline uptake from 4400 (600) cpm (mean (SEM)) to about 22 000 (2000) cpm when EGF was added at 1. 6 nM). EGF(44-53) and EGF(49-53) did not stimulate (3)H thymidine uptake. Control rats had 47 (4) mm(2) damage/stomach, EGF(1-51), EGF(1-52), and EGF(1-53) at 0.16 and 0.80 nmol/kg/h each reduced gastric injury by about 50% and 80%, respectively (both doses p<0.01 compared with control but no significant difference between the different forms). EGF was stable at room temperature for seven days but biological activity decreased by 35% and 40% at two and three weeks, respectively (both p<0.01). Exposure to light did not affect bioactivity. CONCLUSION: EGF(1-51) and EGF(1-52) are as biologically active as full length EGF(1-53) but the C terminal penta- and decapeptides are ineffective. Clinical trials of EGF can probably use infusion systems for at least 48 hours at room temperature and with exposure to light, without reducing biological efficacy.

Analysis of Variance↗