Functional and metabolic evaluation of the hypertrophied heart using MRI and 31P-MRS

Most patients with cystic fibrosis require oral administration of pancreatic enzymes to treat pancreatic insufficiency. Recent use of higher-strength enzyme preparations in large doses has been found to be associated with fibrotic strictures of the colon. We report a case of pancolonic fibrosis due to pancreatic enzyme use.     

Comparative effects of enteric-coated pancreatin microsphere therapy after conventional and pylorus-preserving pancreatoduodenectomy

BACKGROUND: A comparative study was performed between patients with exocrine pancreatic insufficiency after conventional pancreatoduodenectomy (Whipple's procedure) and pylorus-preserving pancreatoduodenectomy (PPPD). In these patients the pharmacodynamics of 2-mm enteric-coated pancreatin microspheres (ECPMs) and their gastric transit time in relation to that of a solid meal were investigated. The efficacy of ECPM preparations may differ after Whipple's procedure compared with PPPD, because the latter procedure does not include gastrectomy. METHODS: Gastric transit was assessed by double-isotope scintigraphy. A pancake meal was labelled with 99mTc. ECPMs were cold-labelled with 170Er and neutron activated shortly before ingestion to enable imaging with a gamma camera. Intraluminal pancreatic enzyme activity was assessed during a 6-h period with two indirect tests: the cholesteryl [14C]octanoate breath test and the N-benzoyl-L-tyrosyl-p-aminobenzoic acid-p-aminosalicylic acid (NBT-PABA-PAS) test. RESULTS: In patients who had Whipple's procedure, the gastric transit time of ECPMs and of the pancake meal was not significantly different. The outcome of the indirect pancreatic function tests during enzyme supplementation was comparable, and not significantly different, from that in healthy volunteers. In patients who had PPPD, however, the gastric transit time of microspheres was greatly delayed compared with that of the pancake meal (P < 0.05). Improvement in the outcome of the indirect pancreatic function tests during enzyme supplementation was much less and remained well below that of healthy volunteers (P < 0.05). CONCLUSION: In cases of exocrine pancreatic insufficiency after Whipple's procedure, 2-mm ECPM treatment adequately restores pancreatic enzyme activity. Following PPPD, however, ECPM treatment is often ineffective because the microspheres are retained in the stomach. In these patients, use of conventional powdered pancreatin enzyme preparations may improve the efficacy of treatment.     

Complex formation of the nonstructural protein 3 of hepatitis C virus with the p53 tumor suppressor

BACKGROUND: Length of survival of females with cystic fibrosis is worse than it is in males. Results of current research have shown an important correlation among dietary intake, nutritional status, lung function, and survival. The purpose of this study was to explore gender differences in dietary intake and pancreatic enzyme replacement therapy in males and females with cystic fibrosis. METHODS: The study was a cross-sectional measurement of clinical characteristics, energy, and fat intakes in males and females attending the cystic fibrosis outpatients clinics of the John Hunter Hospital, Newcastle, Australia. Twenty-nine subjects, (17 females and 12 males), completed 4-day weighed food records to measure total energy intake and the contribution of macronutrients and to document use of pancreatic enzyme replacement therapy. Energy intake was assessed as the percentage of the recommended energy intake for age and sex. RESULTS: Females with cystic fibrosis had significantly lower energy and fat intakes than males, whereas the females used significantly more pancreatic enzyme replacement therapy. There were no significant differences in clinical characteristics between groups. CONCLUSION: The results support the possibility that gender differences in the energy and fat intakes of older patients may contribute to differential median survival time of males and females with cystic fibrosis.     

Clinical significance of the tests used in the diagnosis of pancreatic diseases

Different methods available for investigating patients for pancreatic disease are discussed. They first include measurement of pancreatic enzymes in biological fluids. Basal amylase and/or lipase in blood are truly diagnostic in acute pancreatitis but their utility is low in chronic pancreatic diseases. Evocative tests have been performed to increase the sensitivity of blood enzyme measurement. The procedure is based on enzyme determination following administration of pancreozymin and secretin, and offers a valuable aid in diagnosis of chronic pancreatitis and cancer of the pancreas. They are capable of discerning pancreatic lesions but are not really discriminatory because similar changes are observed in both diseases. The measurement of urinary enzyme levels in patients with acute pancreatitis is a sensitive indicator of disease. The urinary amylase excretion rises to abnormal levels and persists at significant values for a longer period of time than the serum amylase in acute pancreatitis. The fractional urinary amylase escretion seems to be more sensitive than daily urinary measurement. The pancreatic exocrin function can be assessed by examining the duodenal contents after intravenous administration of pancreozymin and secretin. Different abnormal secretory patterns can be determinated. Total secretory deficiency is observed in patients with obstruction of excretory ducts by tumors of the head of the pancreas and in the end stage of chronic pancreatitis. Low volume with normal bicarbonate and enzyme concentration is another typical pattern seen in neoplastic obstruction of escretory ducts. In chronic pancreatitis the chief defect is the inability of the gland to secrete a juice with a high bicarbonate concentration; but in the advanced stage diminution of enzyme and volume is also evident. Diagnostic procedures for pancreatic diseases include digestion and absorption tests. The microscopic examination and chemical estimation of the fats in stool specimens in different conditions of intake are still important screening tests. Isotopic estimates of steatorrhea and distinction between labeled triolein and oleic acid absorption do not provide greater diagnostic discrimination than traditional procedures. 131I labeled proteins permit a good evaluation of a negative nitrogen balance. Sophisticated procedures to estimate exocrine pancreatic insufficiency are based on the study of endoluminal digestive processes at several times and different level of the small intestine. They permite esclusion of extrapancreatic factors interfering in digestion and absorption functions. The endocrin pancreatic function is evaluated by mean of oral tolerance test an radioimmunoassay of blood insulin. It is generally agreed that "diabetes" caused by insulin deficiency and digestion and absorption defects are the result of diffuse pancreatic destruction. Many methods are now available investigating patients with pancreatic disease but the single use of one of them is never satisfactory...     

Cystic fibrosis: present and future

Cystic fibrosis (CF) is an inherited disorder of epithelial chloride transport affecting primarily pancreas, lungs, gut, liver and exocrine glands. The defect is caused by defects of the cystic fibrosis transmembrane regulation gene on chromosome 7. Genotyping has proved useful in identifying gene carriers, a definitive diagnosis, and in antenetal diagnosis. Genotype/phenotype relationships have shown that the commonest cause of pancreatic insufficiency is the D F508 mutation. Clinical trials are exploring the use of somatic gene therapy but this is not yet a viable treatment option. Liver, lung and intestinal disease result in malnutrition which causes further dysfunction of these organs. Aggressive nutritional and pancreatic enzyme therapy results in improved disease, normal growth and increased survival. However, high-dose enzyme therapy may in some individuals cause a fibrosing colonopathy. For those with end-stage liver and lung disease, transplantation holds out some hope.     

MHC class II gene silencing in trophoblast cells is caused by inhibition of CIITA expression

A. baumannii is a multiresistant bacteria which is recognised as responsible for nosocomial infections and hospital outbreaks. The control of these outbreaks depends on the strain's typing and on the fight's policy against nosocomial infections. An outbreak of A. baumannii is occurred to patients who were hospitalized in Centre Hospitalier de Versailles. To investigate this outbreak, we have determined the biotype (Bouvet's method), the succeptibility pattern (disk diffusion and agar dilution results were analysed with the hierarchical classification and main component analysis) and the total DNA macrorestriction pattern (Pulse Field Gel Electrophoresis using SmaI restriction enzyme). A risk factors for A. baumannii acquisition were delineated in case-control study. During 2 years, 38 patients have been infected or colonized to A. baumannii. Thirty two patients were hospitalized in ICU. We studied 38 non repetitive clinical isolates and 9 strains of the patient's rooms. Four biotypes were defined by the Bouvet's typing method. Fourteen groups were obtained when succeptibility results were analysed with the hierarchical classification and 6 with the main composant analysis. The molecular typing permit us to define 4 epidemic and 6 sporadic strains. All the epidemic strains were isolated on ICU hospitalized patients. Our study has shown wide contamination in patient's rooms (Water tap, dry surfaces, patient's mattresses...). Environmental objects have been a major risk factor for A. baumannii acquisition. The control of this outbreak has been possible by application of hygienic measures (hands washing, isolment, meticulous cleaning of the ICU and environmental controls). No new case is occurred in the last year. Typing methods and case-control study are necessary to investigate cross-infections and take efficient measures against these outbreaks.     

Monitoring of gastric acidity following ductal decompression surgery for chronic pancreatitis

The accepted decompression methods of chronic pancreatitis are the longitudinal pancreaticogastrostomy and the conventional pancreaticojejunostomy. The aim of the present study was to estimate the effect of these types of drainage operations on gastric acidity and to evaluate the clinical results. Between Jan. 1992 to 1996 56 patients with chronic pancreatitis were selected into the investigation who were operated in our clinic. A 24 hour gastric monitoring was taken on every patient before and 6 weeks after the operation. Following a complete postoperative check up we found that both types of operations are effective for pain relief (71%). Retrospectively 83% of the patients had no digestive problems due to pancreatic enzyme substitution. According to our statistical evaluation of 24 hour gastric pH monitoring test no alteration was detected in gastric pH in both groups pre- and postoperatively. On the basis of pH measuring and evaluated data we consider that pancreaticogastrostomy is a good operation choice to relieve intractable pain in selected patients with chronic pancreatitis associated with duct dilatation.     

Theophylline for irreversible chronic airflow limitation: a randomized study comparing n of 1 trials to standard practice

Antibody-directed enzyme prodrug therapy (ADEPT) is a technique to increase antitumor selectivity in cancer chemotherapy. Our approach to this technology has been to design a mutant of human carboxypeptidase A (hCPA1-T268G) which is capable of hydrolyzing in vivo stable prodrugs of MTX and targeting this enzyme to tumors on an Ep-CAM1-specific antibody, ING1. Through the use of this >99% human enzyme which is capable of catalyzing a completely nonhuman reaction, we hope to increase ADEPT selectivity while decreasing overall immunogenicity of the enzyme-antibody conjugate. In the current report, prodrugs of the thymidylate synthase inhibitors GW1031 and GW1843 and the dihydrofolate reductase inhibitor methotrexate were studied for their wild-type and mutant hCPA enzyme hydrolysis, their in vivo stability, and their use in therapy. Prodrugs with high kcat/Km ratios for mutated versus wild-type hCPA1 were examined in vitro for their stability in human pancreatic juice, and in vivo for their stability in mouse plasma and tissues. In addition, targeting and in vivo enzyme activity studies were performed with an ING1 antibody conjugate of the mutant enzyme (ING1-hCPA1-T268G). Finally, in vivo therapy studies were performed with LS174T tumors to demonstrate proof of principle. Results indicate that prodrugs can be synthesized that are selective and efficient substrates of hCPA1-T268G and not substrates of the endogenous CPA activities; this leads to excellent in vivo stability for these compounds. In vivo conjugate targeting studies showed that the antibody-enzyme conjugate was targeted to the tumor and enzyme was initially active in vivo at the site. Unfortunately therapeutic studies did not demonstrate tumor reduction. Experiments to determine reasons for the lack of antitumor activity showed that the enzyme activity decreased as a result of enzyme instability. The results offer encouragement for additional novel mutant enzyme improvements and additional in vivo studies on this unique approach to ADEPT.     

Effect of L-364,718 (CCK receptor antagonist) on exocrine pancreatic secretion of adrenalectomized rats

The exocrine pancreatic secretion of control and adrenalectomized rats treated with L-364,718 was studied. The blockade of the action of endogenous cholecystokinin (CCK) in the control animals was reflected in a reduction of basal pancreatic secretion. This effect was reversed by the administration of submaximal doses of CCK-8. Under treatment with L-364,718, no decrease in pancreatic weight was observed. From this it may be deduced that factors other than CCK act on the pancreas to maintain the processes of enzyme synthesis and storage. Adrenalectomy reduced the weight of the pancreata; the main cause of this was the depletion of zymogen granules, which has been reported in adrenalectomized rats and is accompanied by a reduction in enzyme secretion, especially that of amylase. By contrast, the administration of L-364,718 from the very first moments after adrenalectomy leads to a retention of pancreatic enzymes. This effect is reflected in the maintenance of pancreatic weight and a secretory capacity in response to submaximal doses of CCK-8 similar to that of nonadrenalectomized animals. Accordingly, in the absence of glucocorticoids, endogenous CCK dominates the secretory process because when the action of this secretagogue is prevented by the administration of L-364,718, the discharge of proteins able to be secreted in response to a suitable stimulus is inhibited.     

Detection of K-ras gene mutations at codon 12 in the pancreatic juice of patients with intraductal papillary mucinous tumors of the pancreas

BACKGROUND: The authors previously found specific mutations of the K-ras gene at codon 12 in the pancreatic juice of 67% of patients (6 of 9) with pancreatic ductal carcinoma, and the detection of these mutations was useful for diagnosis. This study was performed to detect and evaluate K-ras mutations in pancreatic juice from patients with intraductal papillary mucinous tumor of the pancreas, which is considered a low grade malignancy. The results were interpreted from the viewpoint of clinical significance. METHODS: K-ras mutations were examined using seminested polymerase chain reaction analysis combined with restriction enzyme digestion, followed by nonradioisotopic single strand DNA conformation polymorphism. RESULTS: Twelve of thirteen cases (92%) of intraductal papillary mucinous tumor of the pancreas, confirmed histologically (9 adenomas and 4 carcinomas), and 26 of 43 cases (60%) of ductal carcinoma showed specific K-ras gene mutations in the pancreatic juice. Furthermore, 4 of 22 patients (18%) with chronic pancreatitis, followed for more than 1 year without a sign of pancreatic tumor, showed K-ras mutations. In contrast, no mutations of the K-ras gene were detected in the pancreatic juice from 28 normal controls. CONCLUSIONS: K-ras mutations were found in the pancreatic juice of all but one patient with intraductal papillary mucinous tumor of the pancreas, but they were not useful for distinguishing carcinoma from adenoma. The authors concluded that K-ras mutations are not a specific marker for pancreatic neoplasms because similar mutations were detected in the pancreatic juice from patients with chronic pancreatitis. At the present time, the detection of K-ras mutations in pancreatic juice should be used clinically as an adjunct diagnostic modality for pancreatic diseases.     

Subclinical chronic pancreatitis in type I hyperlipoproteinemia

Severe pancreatic exocrine insufficiency was demonstrated in a 41 year old man with familial type I hyperlipoproteinemia (fat-induced hyperlipemia). Plasma triglyceride concentration failed to increase significantly with increased dietary fat intake, and fecal fat excretion was markedly increased. Indices of intestinal function were normal. Pancreatic enzyme therapy resulted in reduced fat excretion and increased plasma triglyceride concentration. Secretin stimulation tests revealed impaired duodenal fluid volume, bicarbonate and pancreatic enzyme responses. Insulin-dependent diabetes mellitus had been diagnosed three years earlier. No attacks of acute pancreatitis had occurred in the preceding 20 years, and it is suggested that pancreatic damage may have resulted from repeated subclinical pancreatic insults due to elevated plasma lipid levels. This report is the first to indicate that pancreatic exocrine insufficiency may occur as a late complication of hyperlipemic disorders in the absence of recurrent acute pancreatitis. Steatorrhea may not be apparent because of therapeutic restriction of dietary fat, and the first manifestation of pancreatic exocrine disease may be an amelioration of fat-induced hyperlipemia.     

Left ventricular shape analysis from three-dimensional echocardiograms

Cystic fibrosis patients require pancreatic enzyme supplements to aid food digestion. It is suspected that incorrect delivery of this enzyme may result in both significant malabsorption and the development of strictures in the proximal colon caused by the high-dose supplement reaching this region before the food. Investigations into the drug's delivery were performed using dual-isotope imaging; a method was developed to directly label the enteric-coated enzyme pellets with 111In, re-applying the enteric coating afterwards, and this was then ingested with a pancake meal labelled with 99Tcm-tin colloid. Consecutive image data, acquired over a period of > or = 4 h using a dual-headed gamma camera, were analysed to assess intestinal transit. In-vitro stability checks on these labelling techniques were encouraging, showing < 2% 99Tcm and < 7% 111In elution over 90 min in hydrochloric acid. In 5 of the 12 patients studied to date, the pellets were seen to pass through significantly faster than the food, with a mean difference in 50% gastric emptying time of greater than 93 min. The mean absolute difference in emptying time for all 12 patients was > 67 min. Thus, a technique has been developed to effectively radiolabel pancreatic enzyme pellets, and analysis of dual-isotope images using this preparation, together with radiolabelled solid food, has demonstrated significant differences in the transit of these two substances through the gastrointestinal tract of some cystic fibrosis patients.     

A system for the quantitation of DNA using a microtiter plate-based hybridization and enzyme amplification technology

A quantitative hybridization technique for the detection of plasmid DNA by the action of a nuclease enzyme is described. The process utilizes the specific capture and detection of a sandwich hybridization, in a microtiter plate, that occurs in a single step. The detector probe is labeled with nuclease P1. The pH-dependent specificity of this enzyme for 3'-dinucleotides is used to generate a measurable signal by activating apo-glucose oxidase, which triggers an enzyme amplification cascade in the same microtiter plate. The sensitivity of the assay system is demonstrated in an assay of a mutated form of the human pancreatic ribonuclease gene inserted into the plasmid pUC 18. The system was able to detect 35 amol of target DNA in an assay composed of a 60-min hybridization and 20 min of signal generation. This use of nuclease P1 as the enzyme label and apo-glucose oxidase as the trigger for the amplification cascade results in an assay that is more sensitive than previously described enzyme amplification systems using colorimetric detection.     

Pancreatic bile salt-dependent lipase activity in serum of normolipidemic patients

Bile salt-dependent lipase (BSDL, E.C. 3.1.1.-) is a digestive enzyme secreted by the pancreatic acinar cell. Once in the duodenum, the enzyme, upon activation by primary bile salts, hydrolyzes dietary lipid esters such as cholesteryl esters and lipid-soluble vitamin esters. This enzyme is partially transferred from the duodenum or pancreas to the circulation where it has been postulated to exert a systemic action on atheroma-generating oxidized-low density lipoprotein (LDL). In the present study, sera from 40 healthy normolipidemic volunteers were used to investigate the possible linkage between circulating BSDL, lipids, and lipoproteins. We showed, firstly, that pancreatic-like BSDL activity can be detected in these serums. Secondly, BSDL activity increased significantly with the level of LDL-cholesterol and was also positively linked to the serum concentration of Apo B100 and Apo A-I. Thirdly, we also established that BSDL was associated with LDL, in part by a specific interaction with Apo B100, while no interaction was found with Apo A-I. No linkage with other recorded parameters (triglycerides, phospholipids, and high density lipoprotein-cholesterol) was detected. Because an increase in LDL-cholesterol represents an important risk factor for atheroma, the concomitant increase in BSDL, which can metabolize atherogenic LDL, suggests for the first time that this circulating enzyme may exert a positive effect against atherosclerosis.     

Lysophospholipase-catalyzed hydrolysis of lysophospholipids in Mycoplasma gallisepticum membranes

Mycoplasma gallisepticum strains have a membrane-bound lysophospholipase which hydrolyzes lysophospholipid generated in these membranes by treatment with an external phospholipase. This paper studies the hydrolysis of the membranous lysophospholipids by an enzyme residing in the same membrane (intramembrane utilization) or in adjacent membranes (intermembrane utilization). To study intermembrane hydrolysis, the phospholipids of M. gallisepticum were labeled with [3H]oleic acid. Membranes were prepared, heated at 65 degrees C, and subsequently treated with pancreatic phospholipase A2. This resulted in membranes whose enzyme was heat inactivated, but which contained lysophospholipid. When these membranes were mixed with M. gallisepticum cells or membranes, the lysophospholipid was hydrolyzed by the membranous lysophospholipase. To study intramembrane hydrolysis, [3H]oleyl-labeled membranes of M. gallisepticum were treated with pancreatic phospholipase A2 at pH 5.0. At this pH, lysophospholipid was generated but not hydrolyzed. Adjustment of the pH to 7.4 resulted in hydrolysis of the lysophospholipid by the membranous lysophospholipase. These procedures permitted measuring the initial rates of intramembrane and intermembrane hydrolysis of the lysophospholipid, showing that the time course and dependence on endogenous substrate concentration were different in the intramembrane and intermembrane modes of utilization. They also permitted calculation of the molar concentration of the lysophospholipid in the membrane and its rate of hydrolysis, expressed as moles per minute per cell or per square centimeter of cell surface.     

Bcl-2 expression and apoptosis in nephrotoxic nephritis

The aim of this paper is to present a conceptual and practical framework of the case-control design in medical research. To illustrate this method, practical examples directed to clinicians and other health professionals interested in medical research are presented. The case-control method is very versatile and allows for multiple applications. Guidelines for the selection of cases and controls, and some considerations on sample size are presented. In the statistical analysis we use concrete examples of how to estimate odds ratios, confidence intervals, and methods to control for potential confounders, from stratified analysis to logistic regression.     

Effect of somatostatin immunoneutralization on gastric acid and pancreatic enzyme secretion in anesthetized rats

The involvement of somatostatin in urethane-anesthesia-evoked suppression of gastric acid secretion has been described. The present study has examined the role of endogenous somatostatin in diminished pancreatic enzyme secretion during anesthesia, while monitoring acid secretion concurrently. Rats were anesthetized with either urethane or sodium pentobarbital. An indwelling catheter was placed into the right jugular vein. The esophagus and the pylorus were ligated, and the stomach was perfused with saline. The common bile duct was ligated at the hepatic hilum, and cannulated at the duodenal end of the duct for collecting pure pancreatic juice. Purified somatostatin monoclonal antibody (CURE.S6) or control antibody (keyhole limpet hemacyanin, KLH) was injected iv in increasing doses (0.05; 0.15; 0.5; and 1.5 mg) every 30 min (n = 6). Gastric acid and pancreatic amylase secretions were measured. The effect of the antibodies on CCK-8-stimulated (0.25-2.50 nmol/kg/h) pancreatic amylase secretion was also tested. During urethane anesthesia somatostatin antibody induced a dose-dependent increase in acid output, while control antibody did not change it. Basal pancreatic amylase secretion was not affected by either somatostatin or by control antibody. Pancreatic secretory responses to high but not to low doses CCK-8 were found to be significantly increased following immunoneutralization of somatostatin. In sodium pentobarbital-anesthetized rats somatostatin antibody stimulated basal acid secretion but did not affect basal pancreatic amylase secretion. Our data indicate that in anesthetized rats endogenous somatostatin mediates suppression of basal gastric acid secretion but not that of basal pancreatic amylase secretion, and this action does not depend on the type of anesthesia. Furthermore, endogenous somatostatin may play a physiological role in modulating stimulated pancreatic enzyme secretion in this species.     

Women''s opinion on abortion legalization in a middle size county in southern Brazil

To study pancreas enzyme content regulation when the diet was modified in suckling goats, a comparison was made between kids fed a milk replacer and ones fed maternal milk. A total of 25 preruminant Granadina breed goats were bottle-fed a milk replacer ad libitum from postnatal days 3 to 28 (until the age of 3 days kids had been fed colostrum). Body weight, pancreas weight, total protein concentration, and enzyme activities in pancreatic tissue were determined at 3, 7, 14, 21 and 28 days of age, and the results were compared to those previously obtained in kids fed maternal milk for the same period. Lipase activity was significantly lower in the group fed milk replacer, which was poorer in fat. Amylase activity was higher in this group, perhaps due to the starch products present in the milk substitute. However, the postnatal evolution of chymotrypsin activity followed a similar pattern regardless of diet. Our results seem to confirm that in preruminant kids there is a nutritional regulation of pancreatic amylase and lipase activities, depending on the amounts of their respective substrates in the diet, similar to that described in nonruminants.     

Signaling pathways controlling trophoblast cell differentiation: Src family protein tyrosine kinases in the rat

A specific method for pancreatic elastase II activity analysis was developed. True elastase II activity could be discriminated from that of elastase I and chymotrypsin. The postnatal development of four pancreatic proteases in the duodenal juice of children and in the pancreatic homogenates of calves and piglets was measured. The study was carried out on patients without (14 children) and with (5 children) pancreatic insufficiency. Calves and piglets were either milk-fed or weaned until slaughter at different ages. Profiles of enzyme development were globally similar in milk-fed piglets and calves, while in children without pancreatic insufficiency, no significant change was observed between 4 and 168 months. In children with pancreatic insufficiency, enzyme activity was low. In animals, elastase II and chymotrypsin activities were maximal at birth, decreased with age, and probably were associated with the digestion of milk protein. In contrast, elastase I and trypsin activities increased markedly after weaning in connection with the intake of solid food.     

Lack of dose-response with Pancrease MT for the treatment of exocrine pancreatic insufficiency in adults

BACKGROUND: Choosing the optimum pancreatic enzyme replacement therapy for patients with exocrine insufficiency remains a problem. An enteric coated enzyme microsphere pancreatic enzyme preparation (Pancrease) has been marketed with several levels of lipase activity, implying that there is a dose-response relationship between dose and effectiveness such that the high potency form appears to be the most cost effective. METHODS: In a randomized, single-blind, cross-over study, we evaluated the effectiveness of a commercial enzyme preparation with different amounts of lipase per dosage unit in adults with exocrine pancreatic insufficiency. Patients received a diet comprising 100 g fat each day for 6 days. With each meal (three per day) they received two capsules of either Pancrease MT4 (8000 unit lipase), Pancrease MT10 (20,000 units lipase), Pancrease MT16 (32,000 units lipase) or placebo. A 72-h quantitative faecal collection was carried out for the last 3 days of the 6-day period. RESULTS: There was a reduction in faecal fat excretion with each of the preparations compared to placebo. The difference failed to reach significance with the 8000 units lipase preparation (P > 0.05) but was significant (P = 0.02) with the 20,000 units lipase and the 32,000 units lipase preparations (faecal fat excretion: placebo = 42.1 +/- 29 g, lipase 8000 = 22.1 +/- 7.3 g, lipase 20,000 = 10.2 +/- 4.5 g and lipase 32,000 = 15.8 +/- 12.5 g, P < for 20,000 units and 32,000 units lipase compared to placebo). CONCLUSION: A dose-response relationship between the amount of lipase administered with each meal and a reduction in faecal fat was not evident. The most potent preparation did not provide additional benefits compared to the less expensive lower potency dosage form.