Predicting relapse in Crohn's disease: a biopsychosocial model.

BACKGROUND: Crohn's disease (CD) is a chronic relapsing inflammatory bowel disorder. Both biological and psychosocial factors may modulate the illness experience. AIM: The aim of this study was to identify clinical, biological and psychosocial parameters as predictors of clinical relapse in quiescent CD. METHODS: Patients in medically induced remission were followed prospectively for 1 year, or less if they relapsed. Disease characteristics were determined at baseline. Serum cytokines, anti-Saccharomyces cerevisiae antibodies, C-reactive protein (CRP), erythrocyte sedimentation rate and intestinal permeability were measured every 3 months. Psychological distress, perceived stress, minor life stressors and coping strategies were measured monthly. A time-dependent multivariate Cox regression model determined predictors of time to relapse. RESULTS: 101 patients (60 females, 41 males) were recruited. Fourteen withdrew and 37 relapsed. CRP (HR = 1.5 per 10 mg/l, 95% CI 1.1 to 1.9, p = 0.007), fistulising disease (HR = 3.2, 95% CI, 1.1 to 9.4, p = 0.04), colitis (HR = 3.5 95% CI 1.2 to 9.9, p = 0.02) and the interaction between perceived stress and avoidance coping (HR = 7.0 per 5 unit increase for both scales, 95% CI 2.3 to 21.8, p = 0.003) were predictors of earlier relapse. CONCLUSIONS: In quiescent CD, a higher CRP, fistulising disease behaviour and disease confined to the colon were independent predictors of relapse. Moreover, patients under conditions of low stress and who scored low on avoidance coping (ie, did not engage in social diversion or distraction) were least likely to relapse. This study supports a biopsychosocial model of CD exacerbation.

Kinetic constants for receptor-dependent and receptor-independent low density lipoprotein transport in the tissues of the rat and hamster.

In this study, carried out in the rat and hamster, the receptor-dependent low density lipoprotein (LDL) transport process in each organ was characterized in terms of its maximal uptake rate (Jm) and Michaelis constant (Km), while the rate of receptor-independent uptake was defined in terms of its proportionality constant (P). The highest Jm values of 50-126 micrograms/h per g were found in the liver and endocrine glands in both species and receptor-dependent uptake also was detected in other organs like spleen, kidney, and intestine. The Km values were essentially the same in all of the organs and equaled approximately 90 mg/dl in both species. The receptor-independent uptake constants also were similar in the two species and were highest in the spleen, liver, and intestine. From these values for Jm, Km, and P, it was possible to construct theoretical curves that predict the plasma LDL-cholesterol concentration and fractional catabolic rate given any alteration in LDL-cholesterol production or the magnitude of receptor-dependent LDL transport in any organ of the rat or hamster.

Glucose transport and microvillus membrane physical properties along the crypt-villus axis of the rabbit.

Both transport function and microvillus membrane physical properties evolve as the enterocyte matures and migrates up the crypt-villus axis. We isolated enriched fractions of villus tip, mid-villus, and crypt enterocytes from which microvillus membrane vesicles were prepared. Using this material we characterized the alterations that occur in microvillus membrane fluidity as the rabbit enterocyte matures and correlated these with kinetic studies of glucose transport. With increasing maturity the microvillus membrane becomes more rigid due to both an increase in the cholesterol/phospholipid ratio and alterations in individual phospholipid subclasses. Maximal rates of glucose transport were greatest in microvillus membrane vesicles prepared from mature cells. However, the glucose concentration producing half-maximal rates of transport (Km) was significantly lower in crypt microvillus membrane vesicles, suggesting that a distinct glucose transporter existed in crypt enterocytes. This distinction disappeared when differences between membrane lipid environments were removed. By fluidizing villus-tip microvillus membrane vesicles, in vitro, to levels seen in the crypt microvillus membrane, we observed a reduction in the Km of this transport system. These data suggest that the kinetic characteristics of the sodium-dependent glucose transporter are dependent upon its local membrane environment.

The safety, tolerance, pharmacokinetic and pharmacodynamic effects of single doses of AT-1001 in coeliac disease subjects: a proof of concept study.

BACKGROUND: Lifelong adherence to a strict gluten-free diet is the cornerstone of coeliac disease treatment. Elucidation of disease pathogenesis has created opportunities for novel therapeutic approaches to coeliac disease. AT-1001 is an inhibitor of paracellular permeability whose structure is derived from a protein secreted by Vibrio cholerae. AIM: To determine the safety and tolerability of 12 mg doses of AT-1001 in coeliac disease subjects challenged with gluten. METHODS: An in-patient, double-blind, randomized placebo-controlled safety study utilizing intestinal permeability, measured via fractional excretions of lactulose and mannitol, as an exploratory measure of drug efficacy. RESULTS: Compared to placebo, no increase in adverse events occurred in patients exposed to AT-1001. Following acute gluten exposure, a 70% increase in intestinal permeability was detected in the placebo group, while none was seen in the AT-1001 group. Interferon-gamma levels increased in four of seven patients (57%) of the placebo group, but only in four of 14 patients (29%) of the AT-1001 group. Gastrointestinal symptoms were more frequently detected in the placebo group when compared to the AT-1001 group (P = 0.018). CONCLUSIONS: AT-1001 is well tolerated and appears to reduce intestinal barrier dysfunction, proinflammatory cytokine production, and gastrointestinal symptoms in coeliacs after gluten exposure.

Intestinal mucosal dysfunction and infection during remission-induction therapy for acute myeloid leukaemia.

Intestinal barrier function was prospectively examined in the course of a clinical trial evaluating the efficacy and safety of lisofylline for reducing cytotoxic therapy-induced intestinal epithelial damage-related infectious morbidity in patients receiving standard remission-induction therapy for acute myeloid leukaemia. The absorption and permeation of oral D-Xylose, lactulose and mannitol were measured weekly from baseline until marrow recovery in adult recipients of idarubicin plus cytarabine for untreated acute myeloid leukaemia. These studies were correlated with non-haematologic chemotherapy-related toxicities reflecting mucosal damage, including nausea, vomiting, stomatitis, diarrhoea, abdominal pain and systemic infection. D-xylose absorption decreased and lactulose:mannitol ratio reflecting intestinal permeability increased from baseline until the second and third week after the beginning of the treatment followed by recovery. These measures correlated with infection rates, nausea, vomiting, diarrhoea and increased blood product utilization. Lisofylline was associated with increased intestinal permeability, nausea, vomiting and infection-related morbidity despite a reduction in the duration of neutropaenia. These surrogates of intestinal barrier function correlated well with clinically important outcomes despite the failure to demonstrate reduced morbidity with lisofylline and represent useful objective outcome measurements for future clinical trials of products for the amelioration of the effects of cytotoxic therapy on the intestinal mucosa.

Lipid permeability of rat jejunum and ileum: correlation with physical properties of the microvillus membrane.

It is now generally accepted that dietary lipids permeate through the cholesterol-phospholipid bilayer of the intestinal microvillus membrane during the process of intestinal absorption. Therefore, it has been assumed that rates of lipid permeation depend upon the physical properties of the microvillus membrane. In this study the lipid permeability properties of the microvillus membrane were compared in two regions of the intestine, jejunum and ileum. Since the jejunum is exposed to the majority of dietary lipid it would be reasonable to suppose that it would be more efficient at lipid absorption. The ileum was found to be less permeable to all fatty acids examined and this could be correlated with increased rigidity of ileal microvillus membrane vesicles measured with multiple fluorescent probes. Differences in membrane fluidity were found in both the outer third and central regions of the bilayer. When measurements of membrane fluidity were performed either in the presence or the absence of fatty acids, it could be demonstrated that these acids perturb the physical properties of the outer region or the membrane. Therefore, this suggests that the rate-limiting step in fatty acid permeation may be localized to the outer third of the bilayer. Pharmacologic or dietary manipulations attempting to alter rates of lipid permeability should, therefore, be directed towards altering the physical properties of this region of the microvillus membrane.

Lipid permeability of the intestinal microvillus membrane may be modulated by membrane fluidity in the rat.

Fatty acids and cholesterol permeate across the intestinal microvillus membrane at rates dictated by the hydrophobicity of the permeating lipid and the permeability properties of the microvillus membrane. A theory has evolved suggesting that the chemical composition and physical properties of the microvillus membrane are important in determining microvillus membrane lipid permeability in vivo. This communication reports a test of this hypothesis. To compare in vivo membrane lipid permeability within the same intestinal region, but under conditions were membrane physical properties were radically altered, rats were fed an inhibitor of cholesterol synthesis. This resulted in the replacement of 87-90% of membrane cholesterol with its' precursor, 7-dehydrocholesterol. Marked changes in membrane physical properties were observed, including a reduction in the static and dynamic component of membrane fluidity within the jejunal microvillus membrane. These changes were limited primarily to the outer regions of the bilayer. Associated with these alterations was a pronounced reduction in membrane lipid permeability. Therefore, microvillus membrane lipid permeability, in vivo, appears to be correlated with physical properties of the bilayer, especially those of the superficial regions.

Erythrocyte membrane fluidity in malignant hyperthermia.

Malignant hyperthermia (MH) is a rare but serious complication of general anesthesia that potentially carries a high mortality and morbidity. It is associated with excessive release of calcium into skeletal muscle following exposure to certain drugs, including the volatile general anesthetics. Since these are recognized membrane fluidizing agents it has been speculated that this condition might represent a generalized defect in membrane physical properties either at rest or inducible by fluidizing agents. If this hypothesis were found to be correct, malignant hyperthermia might conveniently be detected by examining membrane physical properties of easily accessible cells rather than the cumbersome method of muscle biopsy currently employed. To test this hypothesis we identified patients proven to be susceptible to MH by muscle biopsy and a cohort of patients not susceptible to MH as defined by negative muscle biopsy testing. Erythrocytes were isolated from both groups and membrane physical properties examined using conventional, widely available, steady-state fluorescence polarization techniques. Erythrocyte membranes were evaluated with multiple probes both in the basal condition and following fluidization with either increasing temperature or two concentrations of a fluidizing alcohol. We report, contrary to previous publications, that no discernable differences were detectable between MH-positive or negative patients. Thus, we find no evidence for a generalized membrane defect in MH and conclude that the determination of erythrocyte membrane physical properties, by these techniques, are of no use in the preoperative screening for this disorder.

Oxidative and drug-induced alterations in brush border membrane hemileaflet fluidity, functional consequences for glucose transport.

Oxidation of biological membranes has been suggested as a major pathological process in a variety of disease states including intestinal ischemia and inflammatory bowel disease. Previous studies on the small intestinal brush border membrane have shown that part of the decrease in the activity of the Na(+)-dependent glucose transporter (SGLT1) observed after oxidation could be secondary to the derangement in membrane fluidity that accompanied oxidative damage. The present study examined the relationship between oxidative-induced hemileaflet fluidity alterations and the resultant change in Na(+)-dependent glucose transport activity. To address this issue, in vitro oxidation of guinea pig brush border membrane vesicles was induced by incubation of the vesicles with ferrous sulfate and ascorbate. We found that oxidation decreased the fluidity of both the outer and inner hemileaflets, the decrease being greater in the outer leaflet. Moreover, the preferential alteration in hemileaflet fluidity was accompanied by a decrease in glucose transport. However, when membrane perturbing agents such as hexanol and A(2)C were used to restore membrane fluidity to levels comparable to controls, rates of glucose transport could not be interpreted in terms of variation of bulk membrane fluidity or variation in fluidity of any specific membrane leaflet. On the basis of these experiments, we propose that previous studies that reported coincidental alteration in membrane fluidity and glucose transport cannot be interpreted on the basis of bulk fluidity or hemileaflet fluidity.

Proline transport across the intestinal microvillus membrane may be regulated by membrane physical properties.

There is now abundant evidence that integral membrane protein function may be modulated by the physical properties of membrane lipids. The intestinal brush border membrane represents a membrane system highly specialized for nutrient absorption and, thus, provides an opportunity to study the interaction between integral membrane transport proteins and their lipid environment. We have previously demonstrated that alterations in this environment may modulate the function of the sodium-dependent glucose transporter in terms of its affinity for glucose. In this communication we report that membrane lipid-protein interactions are distinctly different for the proline transport proteins. Maximal transport rates for L-proline by either the neutral brush border or imino transport systems are reduced 10-fold when the surrounding membrane environment is made more fluid over the physiological range that exists along the crypt-villus axis. Furthermore, in microvillus membrane vesicles prepared from enterocytes isolated from along the crypt-villus axis a similar gradient exists in the functional activity of these transport systems. This would imply that either the functional activity of these transporters are regulated by membrane physical properties or that the synthesis and insertion of these proteins is coordinated in concert with membrane physical properties as the enterocyte migrates up the crypt-villus axis.

Capsaicin effects on non-neuronal plasma membranes.

Capsaicin has been touted as a pharmacological tool specific for sensory afferent neurons and is widely used in neurophysiological studies. However, we have recently demonstrated that in concentrations commonly employed within the gastrointestinal tract, capsaicin inhibits platelet aggregation to at least three different stimuli. Since this was observed in a nerve free system it raised the question of how specific capsaicin is. In this communication we report that capsaicin has profound effects on physical properties of non-neuronal cell plasma membranes. These effects were observed while measuring the effect of capsaicin upon the fluidity of both intact cell membranes and a variety of purified membrane preparations. Membrane fluidity was assessed with the fluorescent probes diphenylhexatriene (DPH) and its trimethylamino derivative TMA-DPH and demonstrated concentration-dependent capsaicin effects. Furthermore, the effects were cell specific and for full expression required both intact cells and a non-lipid extractable component of the plasma membrane. These non-neuronal effects must be carefully considered when contemplating the explanation for capsaicin-induced effects.

The anti-oxidant properties of 5-aminosalicylic acid.

Oxidative damage to biological membranes is an important cause of tissue injury in inflammatory bowel disease. 5-Aminosalicylic Acid (5ASA) has therapeutic efficacy in Ulcerative colitis, which may be based on its antioxidant properties. We used Parinaric acid as a fluorescent marker of oxidation in an intestinal microvillous brush border membrane preparation. Various concentrations of the antioxidants 5ASA, ascorbate, and tocopherol were added, and oxidation was initiated from within the membrane by 2,2' azobis (2.4-dimethylvaleronitrile) (AMVN) and from solution by 2,2' azobis (2-amidinopropane) hydrochloride (AAPH). Tocopherol was able to inhibit oxidation from either source. Ascorbate was only able to inhibit oxidation initiated from solution. 5ASA was able to inhibit oxidation initiated from either site, and was more effective than tocopherol against AAPH, but similarly effective against AMVN. We postulate that water soluble 5ASA preferentially associates with membrane surface, allowing chain-breaking antioxidant activity when peroxidation is initiated within the membrane. Likewise, it is effective against aqueous oxidants because its position allows it to interact with AAPH before lipid peroxidation can be initiated as well as breaking the lipid peroxidation chain once it is initiated. This dual capacity may be important for therapeutic effect of 5ASA and may suggest other candidate antioxidants for clinical trials.

Gastric tolerance of high-dose pulse oral prednisone in multiple sclerosis.

BACKGROUND: Prednisone and methylprednisolone are well absorbed orally and have lower treatment costs than IV methylprednisolone, but concern that low-dose corticosteroid may cause increased disease activity and that high oral doses may cause gastric ulceration inhibits use of oral therapy for MS attacks. METHODS: Gastric mucosal injury, detected by measurement of gastric permeability, was examined after five alternate day doses of IV methylprednisolone (1 g) or oral prednisone (1,250 mg) in 21 patients with MS. A triple sugar test solution was consumed at bedtime, and urine was collected overnight. Urine sugar concentrations were determined by high-pressure liquid chromatography. Gastric permeability was expressed as total mg of sucrose excreted. RESULTS: Seventeen patients completed the protocol (12 oral, 5 IV). Baseline sucrose excretion was normal in all. Both groups demonstrated an increase in gastric permeability after steroid treatment, but there was no difference between the two groups (95% CI 95 to 91 mg, p = 0.96). After treatment, three (25%) patients in the oral group, and two (40%) patients the IV group, had modestly abnormal gastric permeability (95% CI 34 to 64%, P = 0.6). CONCLUSIONS: Short-term high-dose oral prednisone is not associated with greater gastric damage, as measured with permeability tests, than IV methylprednisolone. High-dose oral prednisone should be considered a first-line treatment option for MS attacks.

On the in vitro vasoactivity of bile acids.

We compared the vasorelaxant action of nine different bile acids and correlated their vasorelaxant activity with their individual indices for hydrophobicity or lipophilicity. Vasorelaxant activity correlated with the relative lipid solubility of bile acids with lipophilic bile acids exhibiting the greatest vasorelaxant activity with modest to no vasorelaxant activity exhibited by hydrophilic bile acids. We also investigated whether bile acid-induced vasorelaxation is mediated by antagonism of a prototypal contractile receptor, the alpha(1)-adrenoceptor, by stimulation of a bile acid surface membrane receptor, by the release of endothelium-derived relaxant factors, by promoting the generation of reactive oxygen species and increasing the extent of lipid peroxidation, or by modifying membrane fluidity. Lipophilic bile acids induce vasorelaxation possibly by antagonizing alpha(1)-adrenoceptors, a phenomenon that manifests itself as a lowering of the affinity of vascular alpha(1)-adrenoceptors. Bile acid-induced vasorelaxation was not dependent upon stimulation of a bile acid surface membrane receptor or the release of endothelium-derived relaxant factors. Lipophilic bile acids can also increase the extent of lipid peroxidation with a subtle reduction in the fluidity of rat vascular smooth muscle membranes not associated with loss of membrane cholesterol or phospholipid. We have concluded that lipophilic bile acids are non-selective vasorelaxants whose mechanism of action is a multifaceted process involving antagonism of contractile surface membrane receptors possibly effected by an increased extent of lipid peroxidation and/or membrane fluidity but occurs independent of the release of endothelial-derived relaxant factors or stimulation of a surface membrane bile acid binding site.

Intestinal permeability and postheparin plasma diamine oxidase activity in the prediction of Crohn's disease relapse.

A method of detecting presymptomatic relapse of Crohn's disease could allow for the selective use of maintenance or intensified medical therapy in those with an increased risk of relapse. The aim of this study was to evaluate three potential laboratory markers of relapse: intestinal and gastroduodenal permeability and plasma diamine oxidase activity. Intestinal permeability (lactulose/mannitol test), gastroduodenal permeability (urinary sucrose excretion), and postheparin plasma diamine oxidase activity were serially measured in 61 adults with Crohn's disease in remission (CDAI <150) for at least 30 days. Subjects were followed periodically for clinical relapse (CDAI >150 and increased by at least 100 points or the need for steroids or surgery). Fourteen patients (23%) relapsed. A cut-off of 0.030 for the lactulose/mannitol ratio was defined. Those with ratios above the cutoff had a 7.0 times greater risk of relapse (p<0.001). Three subjects who went from a normal ratio to an abnormal ratio relapsed, whereas none of 32 subjects with a repeatedly normal ratio relapsed. Sucrose excretion and plasma diamine oxidase activity did not predict relapse. Serial testing of intestinal permeability, but not of gastroduodenal permeability or plasma diamine oxidase activity, was useful in predicting relapse in asymptomatic patients.

Review article: Intestinal permeability in Crohn's disease.

Measurements of intestinal permeability (IP) may help in determining susceptibility for the development of Crohn's disease or for imminent relapse in patients with the disease. It is now apparent that a subset of patients at high risk for the development of Crohn's disease have either increased baseline IP or an exaggerated response to environmental agents that increase IP. These, coupled with observations that increased IP in patients at risk for the development of Crohn's disease is associated with an abnormal immunological phenotype, lend support to the hypothesis that increased IP is a very early event in the genesis of Crohn's disease.

Substrates for hypothalamic PGE2 synthesis are not decreased in cholestatic rats.

We have recently described impaired IL-1 beta-induced activation of the hypothalamic-pituitary-adrenal (HPA) axis in cholestatic rats and have implicated defective IL-1 beta-mediated hypothalamic generation of PGE2 in this finding. Since patients with obstructive cholestasis have decreased levels of PGE2 precursor fatty acids in their red blood cell membranes (arachidonic acid) we speculated that a similar deficiency of membrane prostaglandin percursor fatty acids in the hypothalamus of cholestatic rats may contribute to the defective cytokine-mediated PGE2 generation we have previously described. Therefore, in this study we determined red blood cell and hypothalamic membrane fatty acid composition in rats with obstructive cholestasis due to bile duct resection and in non-cholestatic sham resected controls 5 days after operation. To do this red blood cell membrane and hypothalamic membrane fatty acids were extracted, methyl esterified and quantified by gas liquid chromatography. Similar to results found in patients with obstructive cholestasis, bile duct resected rats had significantly reduced levels of red blood cell membrane arachidonic acid compared to levels in sham resected controls (p < or = 0.02). However, bile duct resected and sham resected rats had similar levels of hypothalamic membrane arachidonic acid. Therefore, these results suggest that the impaired IL-1 beta-induced HPA axis activation in cholestatic rats cannot be explained by lower hypothalamic membrane levels of the PGE2 substrate arachidonic acid in these animals. Furthermore, our results suggest that the brain in cholestasis appears to be protected from membrane fatty acid composition alterations which are seen outside the blood-brain-barrier.

Complementary and alternative medicine use by patients with inflammatory bowel disease: An Internet survey.

OBJECTIVES: To determine the degree and determinants of the use of complementary and alternative medicine (CAM) by patients with inflammatory bowel disease (IBD) with the use of the Internet and to compare the results with those found by using a similar survey in patients attending gastroenterology clinics in Calgary, Alberta. SUBJECTS AND METHODS: A cross-sectional survey of 263 patients with IBD with the use of a World Wide Web-based, structured questionnaire was conducted. RESULTS: Complementary therapies had been used by 46% of patients in the previous two years. Current use was reported by 34%. Vitamins, herbal products and natural health practices were the most commonly reported therapies. Side effects and lack of effectiveness of standard therapies were the most commonly cited reasons for seeking complementary medicine. However, despite this, respondents who had previously received surgery, or intravenous or oral steroids were less likely to be current CAM users. Important differences between the determinants of and reasons for CAM use in the present study and those of a similar study of IBD patients in a local tertiary care setting were noted. CONCLUSIONS: Complementary medicine use is common in patients with IBD. Differences in the determinants of and reasons for CAM use noted between the present Internet sample and a gastroenterology clinic sample suggest that conclusions from the present study and from previous studies based only on clinic samples provide a limited view of CAM use by people with IBD. More comprehensive assessments are needed.

Giant cell myocarditis, in a patient with Crohn's disease, treated with etanercept--a tumour necrosis factor-alpha antagonist.

Cardiac disease in association with inflammatory bowel disease (IBD) is uncommon. Reports include pericarditis, pericardial effusion, myocarditis, myocardial infarction, endocarditis and arrythmias. Myocardial inflammation related to IBD may be due to a drug hypersensitivity reaction or micronutrient deficiency, or may be secondary to the underlying IBD as an extraintestinal manifestation. In this setting, myocarditis usually presents as congestive heart failure and/or refractory arrhythmia. Prognosis varies among reported cases, including complete recovery, remission with recurrence and fatal disease. Treatment of myocarditis has included aminosalicylates and immunosuppressive medications. Recently, newer therapies for IBD have been developed, such as tumour necrosis factor-alpha (TNF-a) antagonists. The present report describes a case of a 46-year-old man with clinical and endoscopic evidence of moderately active colonic Crohn's disease who developed congestive heart failure due to giant cell myocarditis. Little clinical improvement occurred with immunosuppressive therapy. Only after the addition of etanercept, a TNF-a p75 receptor antagonist, did complete clinical resolution occur. These authors conclude that the use of TNF-a antagonists may be considered in the treatment of life-threatening extraintestinal manifestations of inflammatory bowel disease.

Endoscopists' opinions of indications for upper gastrointestinal endoscopy.

OBJECTIVE: To determine whether endoscopists and general internists agreed with the characterization of appropriateness for endoscopy of various clinical scenarios, as previously reported by the RAND Corporation. DESIGN: Mail survey. STUDY SAMPLE: All endoscopists in western Canada and a random sample of general internists who did not perform endoscopy. METHODS: Questionnaires were sent to 179 endoscopists in western Canada who were asked to rate the 53 scenarios for endoscopy on a nine-point scale ranging from most appropriate to most inappropriate. A similar questionnaire was sent to 39 general internists practising in the province of Alberta. RESULTS: Response rate was 72% of endoscopists (n = 128) and 64% of general internists (n = 25). Among the endoscopists, there was agreement with the RAND classification for 32 scenarios. All 18 indications previously thought to be appropriate were considered to be appropriate. However, endoscopists agreed with only six of 16 equivocal and eight of 19 indications considered inappropriate. Discrepancies were reviewed by five experienced endoscopists and most appeared to be related to a concern regarding possible malignancy linked in part with the definition of failure to respond to medical therapy; and to a refusal to request a barium meal before endoscopy. Among general internists, there was agreement with RAND in 26 scenarios. When the appropriateness rankings of endoscopists and general internists were compared, there was agreement in 40 of 53 scenarios. Significant discrepancies in ratings were identified in scenarios in which barium studies were described as being normal, known or not done. CONCLUSIONS: The equivocal and inappropriate ratings developed by the RAND Corporation are not uniformly accepted by the endoscopy community or general internists. Use of the RAND indications for assessing quality assurance can be challenged.