Proteomic and lipidomics analyses of high fatty acid AhDGAT3 transgenic soybean reveals the key lipase gene associated with the lipid internal mechanism.

Vegetable oil is one of the most important components of human nutrition. Soybean (Glycine max) is an important oil crop worldwide and contains rich unsaturated fatty acids. Diacylglycerol acyltransferase (DGAT) is a key rate-limiting enzyme in the Kennedy pathway from diacylglycerol (DAG) to triacylglycerol (TAG). In this study, we conducted further research using T3 AhDGAT3 transgenic soybean. A high-performance gas chromatography flame ionization detector showed that oleic acid (18:1) content and total fatty acid content of transgenic soybean were significantly higher than those of the wild type (WT). However, linoleic acid (18:2) was much lower than that in the WT. For further mechanistic studies, 20 differentially expressed proteins (DEPs) and 119 differentially expressed metabolites (DEMs) were identified between WT (JACK) and AhDGAT3 transgenic soybean mature seeds using proteomic and lipidomics analyses. Combined proteomic and lipidomics analyses showed that the upregulation of the key DEP (lipase GDSL domain-containing protein) in lipid transport and metabolic process induced an increase in the total fatty acid and 18:1 composition, but a decrease in the 18:2 composition of fatty acids. Our study provides new insights into the deep study of molecular mechanism underlying the enhancement of fatty acids in transgenic soybeans, especially oleic acid and total fatty acid, which are enhanced by over-expression of AhDGAT3.

Production of High-Quality Red Fruit Juices by Athermal Membrane Processes.

Membrane-based processes are increasingly used to clarify and concentrate thermo-sensitive fruit juices and plant extracts as alternatives to conventional processes. This work aimed to evaluate the quality of red fruit juices clarified and concentrated by an integrated membrane process with special regard to the preservation of valuable compounds. A red fruit juice obtained from a blend of pomegranate, cactus pear, and red orange juices of Sicilian origin was clarified by microfiltration (MF) and then pre-concentrated up to 33 °Brix by nanofiltration (NF). The pre-concentrated juice was finally concentrated by osmotic distillation (OD) up to 50 and 60 °Brix. Samples of clarified, pre-concentrated, and concentrated juice were analyzed for their physico-chemical composition and in terms of the antioxidant activity and inhibitory activity against α-amylase and lipase. The results clearly confirmed the assumption of a mild fruit juice processing method, allowing us to preserve the original nutritional and functional properties of the fresh juice. In particular, the OD retentate at 60 °Brix resulted the most active sample against pancreatic lipase and α-amylase inhibitory activity with IC50 values of 44.36 and 214.65 µg/mL, respectively.

Schisandra rubriflora Fruit and Leaves as Promising New Materials of High Biological Potential: Lignan Profiling and Effect-Directed Analysis.

The effect-directed detection (EDD) of Schisandra rubriflora fruit and leaves extracts was performed to assess their pharmacological properties. The EDD comprised TLC-direct bioautography against Bacillus subtilis, a DPPH assay, as well as α-glucosidase, lipase, tyrosinase, and acetylcholinesterase (AChE) inhibition assays. The leaf extracts showed stronger antioxidant activity than the fruit extract as well as inhibition of tyrosinase and lipase. The fruit extract was found to be extremely active against B. subtilis and to inhibit α-glucosidase and AChE slightly more than the leaf extracts. UHPLC-MS/MS analysis was carried out for the bioactive fractions and pointed to the possible anti-dementia properties of the dibenzocyclooctadiene lignans found in the upper TLC fractions. Gomisin N (518 mg/100 g DW), schisanhenol (454 mg/100 g DW), gomisin G (197 mg/100 g DW), schisandrin A (167 mg/100 g DW), and gomisin O (150 mg/100 g DW) were the quantitatively dominant compounds in the fruit extract. In total, twenty-one lignans were found in the bioactive fractions.

Reuse of Food Waste: The Chemical Composition and Health Properties of Pomelo (Citrus maxima) Cultivar Essential Oils.

The aim of the present study is to investigate the chemical profile, antioxidant activity, carbohydrate-hydrolysing enzyme inhibition, and hypolipidemic effect of essential oils (EOs) extracted from Sicilian Citrus maxima (pomelo) flavedo. Using gas-chromatography-mass spectrometry analysis (GC-MS) we analysed the Eos of five cultivars of C. maxima, namely, 'Chadock', 'Maxima', 'Pyriformis', 'Terracciani', and 'Todarii', and their blends. The antioxidant activity was performed by using a multi-target approach using 2,2'-Azino-Bis-3-Ethylbenzothiazoline-6-Sulfonic acid (ABTS), 2,2-Diphenyl-1-picrylhydrazyl (DPPH), ferric reducing ability power (FRAP), and ß-carotene bleaching tests. The α-amylase, α-glucosidase, and lipase-inhibitory activities were also assessed. GC-MS analyses revealed D-limonene as the main monoterpene hydrocarbon in all cultivars, albeit with different percentages in the range of 21.72-71.13%. A good content of oxygenated monoterpenes was detected for all cultivars, especially for 'Todarii'. The analysis of the principal components (PCA), and related clusters (HCA), was performed to find chemo-diversity among the analysed samples. EOs from 'Chadock' and 'Maxima' were statistically similar to each other, and they differed from P3 in the smaller amount of sesquiterpene hydrocarbons, while the oils from 'Terracciani' and 'Todarii' were found to be chemically and statistically different. 'Chadock' EO was the most active to scavenge radicals (IC50 values of 22.24 and 27.23 µg/mL in ABTS and DPPH tests, respectively). 'Terracciani' EO was the most active against both lipase and α-amylase, whereas the blends obtained by the combination (1:1 v/v) of C. maxima 'Maxima' + 'Todarii' were the most active against α-glucosidase. Generally, the blends did not exert a unique behaviour in potentiating or reducing the bioactivity of the pomelo EOs.

Phytochemical Properties and In Vitro Biological Activities of Phenolic Compounds from Flower of Clitoria ternatea L.

Phenolic compounds from the flower of Clitoria ternatea L. (PCFCTL) were extracted using a high-speed shearing extraction technique and purified by AB-8 macroporous resins, and the phytochemical composition of the purified phenolic compounds from the flower of Clitoria ternatea L. (PPCFCTL) was then analyzed. Subsequently, its bioactivities including antioxidant properties, enzyme inhibitory activities, and antiproliferative activities against several tumor cell lines were evaluated. Results indicated that the contents of total phenolics, flavonoids, flavonols, flavanols, and phenolic acids in PPCFCTL were increased by 3.29, 4.11, 2.74, 2.43, and 2.96-fold, respectively, compared with those before being purified by AB-8 macroporous resins. The results showed PPCFCTL have significant antioxidant ability (measured by reducing power, RP, and ferric reducing antioxidant power method, FRAP) and good DPPH, ABTS+, and superoxide anion radical scavenging activities. They can also significantly inhibit lipase, α-amylase, and α-glucosidase. In addition, morphological changes of HeLa, HepG2, and NCI-H460 tumor cells demonstrated the superior antitumor performance of PPCFCTL. However, the acetylcholinesterase inhibitory activity was relatively weak. These findings suggest that PPCFCTL have important potential as natural antioxidant, antilipidemic, anti-glycemic and antineoplastic agents in health-promoting foods.

Bioactive compounds guided diversity of endophytic fungi from Baliospermum montanum and their potential extracellular enzymes.

Baliospermum montanum (Willd.) Muell. Arg, a medicinal plant distributed throughout India from Kashmir to peninsular-Indian region is extensively used to treat jaundice, asthma, and constipation. In the current study, 203 endophytic fungi representing twenty-nine species were isolated from tissues of B. montanum. The colonization and isolation rate of endophytes were higher in stem followed by seed, root, leaf and flower. The phytochemical analysis revealed 70% endophytic isolates showed alkaloids and flavonoids, 13% were positive for phenols, saponins and terpenoids. Further, these endophytes produced remarkable extracellular enzymes such as amylase, cellulase, phosphates, protease and lipase. The most promisive three endophytic fungi were identified by ITS region and secreted metabolites were identified by gas chromatography-mass spectrometry (GC-MS/MS). The GC-MS profile detected twenty-five bioactive compounds from ethyl acetate extracts. Among endophytic fungi, Trichoderma reesei isolated from flower exhibited nine bioactive compounds namely, 2-Cyclopentenone, 2-(4-chloroanilino)-4-piperidino, Oxime-methoxy-Phenyl, Methanamine N-hydroxy-N-methyl, Strychane, Cyclotetrasiloxane, Octamethyl and 1-Acetyl-20a-hydroxy-16-methylene. The endophyte, Aspergillus brasiliensis isolated from root and Fusarium oxysporum isolated from seed produced nine and seven bioactive compounds, respectively. Overall, a significant contribution of bioactive compounds was noticed from the diverse endophytic fungi associated with B. montanum and could be explored for development of novel drug with commercial values.

Zymography for Picogram Detection of Lipase and Esterase Activities.

Lipases and esterases are important catalysts with wide varieties of industrial applications. Although many methods have been established for detecting their activities, a simple and sensitive approach for picogram detection of lipolytic enzyme quantity is still highly desirable. Here we report a lipase detection assay which is 1000-fold more sensitive than previously reported methods. Our assay enables the detection of as low as 5 pg and 180 pg of lipolytic activity by direct spotting and zymography, respectively. Furthermore, we demonstrated that the detection sensitivity was adjustable by varying the buffering capacity, which allows for screening of both high and low abundance lipolytic enzymes. Coupled with liquid chromatography-mass spectrometry, our method provides a useful tool for sensitive detection and identification of lipolytic enzymes.

Enzymatic pretreatment and anaerobic co-digestion as a new technology to high-methane production.

The population growth is causing an increase in the generation of effluents (mainly organic fraction of municipal solid waste (OFMSW) and agro-industrial waste), which is an old problem in agro-industrial countries such as Brazil. Contrastingly, it is possible to add value to these residual biomasses (residues) through the application of new technologies for the production of bioenergy. Anaerobic digestion (AD) of sewage sludge is being applied in many effluent treatment plants for the sustainable and economically viable production of biogas. However, the biogas produced from AD (sludge) or co-digestion (sludge with other residues) presents a concentration of methane between 60 and 70% on average, which is relatively low. This review is aimed at analyzing studies involving (i) production of lipases by solid-state fermentation (SSF) by different microorganisms for the application in enzymatic pretreatments prior to the anaerobic treatment of effluents; (ii) pretreatment followed by AD of various residues, with an emphasis on OFMSW and sewage sludge; and (iii) more recent studies on anaerobic co-digestion (AcoD) and hybrid technologies (pretreatment + AD or AcoD). There are many studies in the literature that demonstrate the enzymatic pretreatment or AcoD applied to the optimization of methane production. Nevertheless, few studies report the combination of these two technologies, which can improve the process and reduce or eliminate the costs of biogas purification, which are major challenges for the viability of this route of bioenergy production. KEY POINTS: • Municipal and agro-industrial wastes have potential as medium for lipase production. • Enzymatic pretreatment and anaerobic co-digestion are low cost for high-methane production. Graphical abstract Interactions among various factors optimization methane production from enzymatic pretreatment and AcoD.

Analysis of clinical characteristics of tigecycline-induced acute pancreatitis.

WHAT IS KNOWN AND OBJECTIVE: The purpose of this study is to explore the clinical characteristics of tigecycline-induced acute pancreatitis. METHODS: We searched the PubMed/Medline, Web of Knowledge, OVID, Elsevier, Springer Link, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang Data, and Chinese VIP databases from 2005 and identified 19 studies of tigecycline-induced acute pancreatitis involving a total of 22 patients for inclusion in a retrospective analysis. RESULTS AND DISCUSSION: The median (range) age of 22 patients with acute pancreatitis was 58 years (range 9-83). Overall, the median (range) time of symptom onset was 6.5 days (range 2-28), or 6 days (range 2-14) and 6 days (range 3-28) in patients with or without a loading dose of tigecycline, respectively. Symptoms included nausea, vomiting and abdominal distension (73%) and abdominal pain (73%); 90% (18/20) of patients developed mild acute pancreatitis (MAP), and 10% (2/20) developed severe acute pancreatitis (SAP). Computed tomography (CT) scans showed oedematous infiltrate in 56% (10/18) of cases and acute pancreatitis in 28% (5/18) of cases. The median (range) level of lipase and amylase was 936U/L (range 382-4089) and 588U/L (range 312-1166), respectively. The median (range) time to recovery of symptoms was 4 days (range 1-10), and the time for recovery of pancreatic enzymes to the normal range was 5 days (range 1-30) after the withdrawal of tigecycline in all patients. WHAT IS NEW AND CONCLUSION: Clinicians should be particularly mindful of clinical signs and symptoms, the level of serum pancreatic enzymes and abdominal CT images in order to monitor the development of pancreatitis when using tigecycline.

Fatal Acute Pancreatitis in an Adolescent: A Case Report.

Acute pancreatitis is uncommon in children and adolescents, and when it does occur, it is rarely fatal. The cause of death may be misdiagnosed as a death due to diabetic ketoacidosis or an infectious disease if an autopsy is not performed. Because these deaths are often unexpected and may occur before medical care, the forensic pathologist may be contacted to determine the cause of death. Even deaths that occur after hospitalization may be referred to the medical examiner because of the concern for drug involvement, the unusual age of the decedent, or the decreased availability for a hospital autopsy. We report a fatal case of acute pancreatitis in a 14-year-old adolescent girl who was brought unresponsive to the emergency room of a university hospital and died after unsuccessful resuscitation efforts.

Masking the Peroxidase-Like Activity of the Molybdenum Disulfide Nanozyme Enables Label-Free Lipase Detection.

Two-dimensional MoS2 nanoparticles (2D-nps) exhibit artificial enzyme properties that can be regulated at bio-nanointerfaces. We discovered that protein lipase is able to tune the peroxidase-like activity of MoS2 2D-nps, offering low-nanomolar, label-free detection and identification in samples with unknown identity. The inhibition of the peroxidase-like activity of the MoS2 2D-nps was demonstrated to be concentration dependent, and as low as 5 nm lipase was detected with this approach. The results were compared with those obtained with several other proteins that did not display any significant interference with the nanozyme behavior of the MoS2 2D-nps. This unique response of lipase was characterized and exploited for the successful identification of lipase in six unknown samples by using qualitative visual inspection and a quantitative statistical analysis method. The developed methodology in this approach is noteworthy for many aspects; MoS2 2D-nps are neither labeled with a signaling moiety nor modified with any ligands for signal readout. Only the intrinsic nanozyme activity of the MoS2 2D-nps is exploited for this detection approach. No analytical equipment is necessary for the visual detection of lipase. The synthesis of the water-soluble MoS2 2D-nps is low costing and can be performed in bulk scale. Exploring the properties of 2D-nps and their interactions with biological materials reveals highly interesting yet instrumental features that offer the development of novel bioanalytical approaches.

The neuropeptide receptor subunit RAMP1 constrains the innate immune response during acute pancreatitis in mice.

OBJECTIVES: The importance of the Calcitonin-gene-related-peptide-pathway (CGRP) as neuronal modulator of innate immune responses in mice has been previously demonstrated. The CGRP-receptor is composed of two subunits: the receptor-activity-modifying-protein-1 (RAMP1) and the calcitonin-receptor-like-receptor (CLR). CGRP can influence immune cells and their capacity of producing inflammatory cytokines. Using a RAMP1 knockout-mouse (RAMP1-/-) we examined the role of the CGRP-receptor in the acute-phase of cerulein-induced pancreatitis. METHODS: Hourly cerulein-injections for a period of 8 h in RAMP1-/- and wild-type mice were performed. To compare severity and extent of inflammation in RAMP1-/- and wild-type mice, histological analyses were done and cytokine levels were assessed using qRT-PCR 8 h, 24 h, 2 days, and 7 days post-cerulein-treatment. Furthermore, serum activities of LDH and lipase were determined. RESULTS: After 8 h RAMP1-/- mice showed a higher pancreas-to-body-weight-ratio, increased tissue edema and immune cell infiltration with higher amount of F4/80-positive cells as compared to wild-type mice. Overall infiltration of immune cells at 24 h was increased in RAMP1-/- mice and composed predominantly of MPO-positive neutrophils. In addition, after 24 h RAMP1-/- mice presented a higher pancreas-to-body-weight-ratio, higher expression of Ccl3, Il6, and Il1b and increased number of cleaved caspase 3 positive cells. Serum lipase correlated with the extent of tissue damage in RAMP1-/- compared to wild-type mice 24 h post-cerulein treatment. CONCLUSION: Mice lacking RAMP1 showed increased inflammation, tissue edema, and pancreas injury particularly in the early phase of acute pancreatitis. This study highlights the essential role of CGRP for dampening the innate immune response in acute pancreatitis.

Ratiometric Nanoparticle Array-Based Near-Infrared Fluorescent Probes for Quantitative Protein Sensing.

Quantitative detection of protein biomarkers is crucial to medical diagnosis. Fluorescent probes have been frequently used for protein detection, but they suffered from various weaknesses such as lack of versatility. In particular, most of the reported probes were not capable of simultaneous qualitative and quantitative detection for various proteins. In this paper, we developed novel nanoparticle array-based near-infrared (NIR) ratiometric probes for potent protein analysis, in which the specific protein was able to be distinguished and quantitated within a group of 11 common proteins. The activity of ß-galactosidases (ß-gal) was temporarily inhibited by the adsorption to magnetic nanoparticles and restored to certain content by replacement with detected proteins, leading to distinctive readout of the enzyme-activatable NIR probe (DCM-ß-gal). The readout of the sensor array against 11 proteins, as verified by isothermal titration calorimetry, was processed and transformed into canonical factors with the help of linear discrimination analysis. Moreover, the ratiometric signals of DCM-ß-gal were translated to quantitatively detect proteins within the concentration range of 0-100 µg/mL. Based on clear differentiation within both two-dimensional and three-dimensional plots, different proteins could be detected with 100% accuracy with their concentration simultaneously determined, which endowed the sensing system with great potential in clinical diagnosis.

Study of pancreatic lipase inhibition kinetics and LC-QTOF-MS-based identification of bioactive constituents of Momordica charantia fruits.

The different parts of Momordica charantia have been reported to have several therapeutic applications against hyperglycemia and hypercholesterolemia associated with pancreatic lipase (PL). Inhibition of this enzyme prevents the absorption of dietary triglyceride in the intestine, and thus exerts an anti-obesity effect. This study aimed to investigate the bioactive constituents of the fruits of M. charantia (MCF) extract and fractions against pancreatic PL followed by study of their inhibition kinetics. The PL inhibitory assay was performed spectrophotometrically by measuring the change in absorbance of the products at 405 nm, using p-nitrophenylcaprylate as substrate. The results indicated that the ethyl acetate fraction of MCF (EFMC) offered significant, dose-dependent inhibition against PL, compared with the positive control, Orlistat. The enzyme kinetics study revealed the inhibition to be a mixed type in nature. Additionally, the total phenol and flavonoid content of the fractions was estimated. A positive correlation between phenolic content of EFMC and its PL inhibitory activity was established statistically, which implied that higher inhibition potential was contributed by the phenolic compounds. The identification of the bioactive constituents was further confirmed by LC-QTOF-MS study. This finding suggested that phenolic compounds of MCF can serve as functional food components to address obesity-related disorders linked with PL.

Secreted Hydrolytic and Haemolytic Activities of Malassezia Clinical Strains.

Malassezia yeasts are opportunistic pathogens associated with a number of skin diseases in animals and humans. The free fatty acids released through these organisms' lipase and phospholipase activities trigger inflammation in the host; thus, these lipase and phospholipase activities are widely recognised as some of the most important factors in Malassezia pathogenesis. In this study, we sought to investigate and examine the relationship between these secreted hydrolytic activities and haemolytic activity in newly isolated Malassezia clinical strains. This characterisation was expected to elucidate pathogenicity of this fungus. We isolated 35 clinical strains of Malassezia spp.; the most frequently isolated species were M. sympodialis and M. furfur. Next, we analysed the hydrolytic activities of all of these clinical isolates; all of these strains (except for one M. dermatis isolate) showed detectable lipase and phospholipase activities against 4-nitrophenyl palmitate and L-α-phosphatidylcholine, dipalmitoyl, respectively. Most of the M. globosa isolates showed higher lipase activities than isolates of other Malassezia species. In terms of phospholipase activity, no significant difference was observed among species of Malassezia, although one isolate of M. globosa showed considerably higher phospholipase activity than the others. All tested strains also exhibited haemolytic activity, both as determined using 5% (v/v) sheep blood agar (halo assay) and by quantitative assay. Although all tested strains showed detectable haemolytic activity, we did not observe an apparent correlation between the secreted lipase and phospholipase activities and haemolytic activity. We infer that the haemolytic activities of Malassezia spp. are mediated by non-enzymatic factor(s) that are present in the secreted samples.

Evaluation of droplet-based microfluidic platforms as a convenient tool for lipases and esterases assays.

The accurate estimation of kinetic parameters is of fundamental importance for biochemical studies for research and industry. In this paper, we demonstrate the application of a modular microfluidic system for execution of enzyme assays that allow determining the kinetic parameters of the enzymatic reactions such as Vmax - the maximum rate of reaction and KM - the Michaelis constant. For experiments, the fluorogenic carbonate as a probe for a rapid determination of the kinetic parameters of hydrolases, such as lipases and esterases, was used. The microfluidic system together with the method described yields the kinetic constants calculated from the concentration of enzymatic product changes via a Michaelis-Menten model using the Lambert function W(x). This modular microfluidic system was validated on three selected enzymes (hydrolases).

Oral lipase activities and fat-taste receptors for fat-taste sensing in chickens.

It has been reported that a functional fat-taste receptor, GPR120, is present in chicken oral tissues, and that chickens can detect fat taste in a behavioral test. However, although triglycerides need to be digested to free fatty acids to be recognized by fat-taste receptors such as GPR120, it remains unknown whether lipase activities exist in chicken oral tissues. To examine this question, we first cloned another fat-taste receptor candidate gene, CD36, from the chicken palate. Then, using RT-PCR, we determined that GPR120 and CD36 were broadly expressed in chicken oral and gastrointestinal tissues. Also by RT-PCR, we confirmed that several lipase genes were expressed in both oral and gastrointestinal tissues. Finally, we analyzed the lipase activities of oral tissues by using a fluorogenic triglyceride analog as a lipase substrate. We found there are functional lipases in oral tissues as well as in the stomach and pancreas. These results suggested that chickens have a basic fat-taste reception system that incorporates a triglycerides/oral-lipases/free fatty acids/GPR120 axis and CD36 axis.

Randomized clinical trial of the effect of a fibrin sealant patch on pancreatic fistula formation after pancreatoduodenectomy.

BACKGROUND: The potential for a fibrin sealant patch to reduce the risk of postoperative pancreatic fistula (POPF) remains uncertain. The aim of this study was to evaluate whether a fibrin sealant patch is able to reduce POPF in patients undergoing pancreatoduodenectomy with pancreatojejunostomy. METHODS: In this multicentre trial, patients undergoing pancreatoduodenectomy were randomized to receive either a fibrin patch (patch group) or no patch (control group), and stratified by gland texture, pancreatic duct size and neoadjuvant treatment. The primary endpoint was POPF. Secondary endpoints included complications, drain-related factors and duration of hospital stay. Risk factors for POPF were identified by logistic regression analysis. RESULTS: A total of 142 patients were enrolled. Forty-five of 71 patients (63 per cent) in the patch group and 40 of 71 (56 per cent) in the control group developed biochemical leakage or POPF (P = 0·392). Fistulas were classified as grade B or C in 16 (23 per cent) and ten (14 per cent) patients respectively (P = 0·277). There were no differences in postoperative complications (54 patients in patch group and 50 in control group; P = 0·839), drain amylase concentration (P = 0·494), time until drain removal (mean(s.d.) 11·6(1·0) versus 13·3(1·3) days; P = 0·613), fistula closure (17·6(2·2) versus 16·5(2·1) days; P = 0·740) and duration of hospital stay (22·1(2·2) versus 18·2(0·9) days; P = 0·810) between the two groups. Multivariable logistic regression analysis confirmed that obesity (odds ratio (OR) 5·28, 95 per cent c.i. 1·20 to 23·18; P = 0·027), soft gland texture (OR 9·86, 3·41 to 28·54; P < 0·001) and a small duct (OR 5·50, 1·84 to 16·44; P = 0·002) were significant risk factors for POPF. A patch did not reduce the incidence of POPF in patients at higher risk. CONCLUSION: The use of a fibrin sealant patch did not reduce the occurrence of POPF and complications after pancreatoduodenectomy with pancreatojejunostomy. Registration number: 2013-000639-29 (EudraCT register).

Analysis of lipase activity in duodenal juice. Comparison of an automated spectrophotometric assay to a fluorometric microplate assay, and factors affecting sample stability.

BACKGROUND: Direct pancreas function testing (DPFT) has been regarded as gold standard for assessment of exocrine pancreas function. One of the outcomes from DPFT is pancreatic lipase activity in duodenal juice, but no standard assay for measuring pancreas lipase activity in duodenal juice exists. AIMS: To optimize and evaluate an autoanalyzer assay for measuring lipase activity in duodenal juice. METHODS: We used samples of duodenal juice from our biobank, collected through a short endoscopic secretin test in patients with suspected exocrine pancreas insufficiency. Samples were analyzed on a Cobas autoanalyzer (Roche Diagnostics), using a colorimetric, kinetic enzyme activity assay. We compared stability of samples diluted in saline to samples diluted in 3-(N-morpholino) propane sulfonic acid (MOPS) buffer added bovine serum albumin (BSA). Results from the Cobas assay were compared to Confluolip method, a fluorometric, kinetic enzyme assay, modified to fit into a microplate setting. RESULTS: We tested the stability of 54 samples from 21 patients. Diluting samples with MOPS buffer added BSA gave stable results, and was superior to diluting samples in saline. We compared the two assays in 50 samples from 20 patients and found a good correlation between the two assays (r = 0.91, p < .001). There was a significant proportional bias between the two assays, but no significant systematic bias. CONCLUSION: Pancreatic lipase activity in duodenal juice samples diluted in MOPS buffer added BSA is stable for one hour at room temperature. Quantification of lipase activity in duodenal juice using a standard automated activity assay has comparable accuracy to a manual fluorometric method.

Rectal Indomethacin Does Not Prevent Post-ERCP Pancreatitis in Consecutive Patients.

BACKGROUND & AIMS: Rectal indomethacin, a nonsteroidal anti-inflammatory drug, is given to prevent pancreatitis in high-risk patients undergoing endoscopic retrograde cholangiopancreatography (ERCP), based on findings from clinical trials. The European Society for Gastrointestinal Endoscopy guidelines recently recommended prophylactic rectal indomethacin for all patients undergoing ERCP, including those at average risk for pancreatitis. We performed a randomized controlled trail to investigate the efficacy of this approach. METHODS: We performed a prospective, double-blind, placebo-controlled trial of 449 consecutive patients undergoing ERCP at Dartmouth Hitchcock Medical Center, from March 2013 through December 2014. Approximately 70% of the cohort were at average risk for PEP. Subjects were assigned randomly to groups given either a single 100-mg dose of rectal indomethacin (n = 223) or a placebo suppository (n = 226) during the procedure. The primary outcome was the development of post-ERCP pancreatitis (PEP), defined by new upper-abdominal pain, a lipase level more than 3-fold the upper limit of normal, and hospitalization after ERCP for 2 consecutive nights. RESULTS: There were no differences between the groups in baseline clinical or procedural characteristics. Sixteen patients in the indomethacin group (7.2%) and 11 in the placebo group (4.9%) developed PEP (P = .33). Complications and the severity of PEP were similar between groups. Per a priori protocol guidelines, the study was stopped owing to futility. CONCLUSIONS: In a randomized controlled study of consecutive patients undergoing ERCP, rectal indomethacin did not prevent post-ERCP pancreatitis. ClincialTrials.gov no: NCT01774604.