-
[show abstract]
[hide abstract]
ABSTRACT: This study aims to update the 1991 Atlanta Classification of acute pancreatitis, to standardize the reporting of and terminology of the disease and its complications. Important features of this classification have incorporated new insights into the disease learned over the last 20 years, including the recognition that acute pancreatitis and its complications involve a dynamic process involving two phases, early and late. The accurate and consistent description of acute pancreatitis will help to improve the stratification and reporting of new methods of care of acute pancreatitis across different practices, geographic areas, and countries.
Surgical Clinics of North America 06/2013; 93(3):549-62. · 2.14 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Acute pancreatitis is the leading cause of hospitalization for gastrointestinal disorders in the United States. As rates of hospitalization for acute pancreatitis continue to increase, so does demand for effective management. We review approaches to best manage patients with acute pancreatitis, covering diagnosis, risk and prognostic factors, treatment, and complications, considering recommendations from current practice guidelines.
Gastroenterology 06/2013; 144(6):1272-81. · 11.68 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The functions of the liver and the pancreas differ; however, chronic inflammation in both organs is associated with fibrosis, which evidence suggests is partially regulated by organ-specific stellate cells. We explore the proteome of human hepatic stellate cells (hHSC) and human pancreatic stellate cells (hPaSC) using mass spectrometry (MS)-based quantitative proteomics to investigate pathophysiologic mechanisms. Proteins were isolated from whole cell lysates of immortalized hHSC and hPaSC. These proteins were tryptically digested, labeled with tandem mass tags (TMT), fractionated by OFFGEL, and subjected to MS. Proteins significantly different in abundance (P < 0.05) were classified via gene ontology (GO) analysis. We identified 1223 proteins and among them, 1222 proteins were quantifiable. Statistical analysis determined that 177 proteins were of higher abundance in hHSC, while 157 were of higher abundance in hPaSC. GO classification revealed that proteins of relatively higher abundance in hHSC were associated with protein production, while those of relatively higher abundance in hPaSC were involved in cell structure. Future studies using the methodologies established herein, but with further upstream fractionation and/or use of enhanced MS instrumentation will allow greater proteome coverage, achieving a comprehensive proteomic analysis of hHSC and hPaSC.
Genomics Proteomics & Bioinformatics 03/2013;
-
[show abstract]
[hide abstract]
ABSTRACT: BACKGROUND: Early diagnosis of chronic pancreatitis by mass spectrometry-based proteomics may result in therapies to retard or modify disease progression. We aimed to identify differences in posttranslational modifications (PTMs) in pancreatic fluid proteins from individuals with chronic pancreatitis (n=9) and non-pancreatitis controls (n=9). METHODS: We collected proteomic data from pancreatic fluid using mass spectrometry techniques. We performed database searches with emphasis on PTMs using ProteinPilot. We compared the frequency of specific PTMs in pancreatic fluid between cohorts and also to those identified in bile, gastroduodenal fluid, urine, and pancreatic duct and stellate cell lysates. RESULTS: We identified 97 PTMs in endoscopically-collected pancreatic fluid, of which 11 were identified exclusively in one cohort and 9 others were significantly different in frequency between cohorts. Comparing pancreatic fluid with other specimens revealed differences in specific PTM frequencies, indicating that the identified PTMs were not merely artifacts of sample processing. CONCLUSIONS: We determined PTMs of proteins extracted from pancreatic fluid which differed in frequency in chronic pancreatitis patients verses controls. Such PTMs may serve as biomarker candidates of chronic pancreatitis upon validation with larger cohorts. The analysis of the PTM profile of pancreatic fluid proteins offers an alternative method to standard protein-based biomarker discovery. BIOLOGICAL SIGNIFICANCE: The early diagnosis of chronic pancreatitis is paramount in developing strategies to modify, retard, or halt disease progression. In the present study, we compared post-transitional modifications (PTMs) of proteins extracted from pancreatic fluid of chronic pancreatitis patients verses a control cohort. With many mass spectrometry-based proteomics workflows aimed to identify and quantify proteins, data for PTMs typically comes gratis, in that such data are collected during protein sequencing and, as such, require only downstream bioinformatics processing. We identified a total of 20 PTMs which were exclusive to or significantly different between cohorts. Upon validation with larger cohorts these PTMs may serve as biomarker candidates of chronic pancreatitis. PTM profiling of pancreatic fluid proteins is complementary to standard protein-based biomarker discovery, and may be readily applied to studies of pancreatic disease.
Journal of proteomics 03/2013; · 5.07 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: : Patients with extensive ulcerative colitis or Crohn's disease of the colon have an increased risk of colon cancer and require colonoscopic surveillance. This study explores factors that affect adherence to surveillance colonoscopy.
: Three hundred and seventy-eight patients with ulcerative colitis or Crohn's disease of the colon for at least 7 years and at least one-third of the colon involved participated in this cross-sectional questionnaire study performed at 3 tertiary referral inflammatory bowel disease clinics.
: Two hundred and eight patients were female and 189 had ulcerative colitis. The mean age was 49.9 years and mean disease duration 22.9 years. The total number of surveillance colonoscopies performed was 1529, and the mean number per patient was 4.01. The mean interval between surveillance colonoscopies was 2.71 years; 282 patients had a mean interval of <3 years. Self-reported adherence was consistently higher than chart-documented adherence. Significant categories of reasons for nonadherence were logistics (P = 0.012), health perceptions (P = 0.0001); stress regarding procedure, job, or personal life (P = 0.0002); and procedure problems (P = 0.001). The most frequently cited most important reason was difficulty with the bowel preparation (18 patients; 4.8%). Of the 26 patients with inflammatory bowel disease-related dysplasia, 3 had cancer, 4 high-grade dysplasia, 15 low-grade dysplasia, and 4 indefinite dysplasia. Detection of dysplasia was not related to adherence or to lack of adherence.
: In this study, 25.5% of our patients underwent surveillance colonoscopies at >3-year intervals on average. Significant categories of reasons for nonadherence included logistics, health perceptions, stress, and procedure problems.
Inflammatory Bowel Diseases 03/2013; 19(3):534-9. · 4.86 Impact Factor
-
Stephen T Amann,
Dhiraj Yadav,
M Micheal Barmada,
Michael O'Connell,
Elizabeth D Kennard,
Michelle Anderson,
John Baillie,
Stuart Sherman,
Joseph Romagnuolo,
Robert H Hawes,
Samer Alkaade,
Randall E Brand,
Michele D Lewis,
Timothy B Gardner,
Andres Gelrud,
Mary E Money, Peter A Banks,
Adam Slivka,
David C Whitcomb
[show abstract]
[hide abstract]
ABSTRACT: OBJECTIVES: The objective of this study was to define the quality of life (QOL) in patients with chronic pancreatitis (CP). METHODS: We studied 443 well-phenotyped CP subjects and 611 control subjects prospectively enrolled from 20 US centers between 2000 and 2006 in the North American Pancreatitis Study 2. Responses to the SF-12 questionnaire were used to calculate the mental (MCS) and physical component summary scores (PCS) with norm-based scoring (normal ≥50). Quality of life in CP subjects was compared with control subjects after controlling for demographic factors, drinking history, smoking, and medical conditions. Quality of life in CP was also compared with known scores for several chronic conditions. RESULTS: Both PCS (38 [SD, 11.5] vs 52 [SD, 9.4]) and MCS (44 [SD, 11.5] vs 51 [SD, 9.2]) were significantly lower in CP compared with control subjects (P < 0.001). On multivariable analyses, compared with control subjects, a profound decrease in physical QOL (PCS 12.02 points lower) and a clinically significant decrease in mental QOL (MCS 4.24 points lower) was seen due to CP. Quality of life in CP was similar to (heart, kidney, liver, lung disease) or worse than (nonskin cancers, diabetes mellitus, hypertension, rheumatoid arthritis) other chronic conditions. CONCLUSIONS: The impact of CP on QOL appears substantial. The QOL in CP subjects appears to be worse or similar to the QOL of many other chronic conditions.
Pancreas 01/2013; · 2.39 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: OBJECTIVES: Subcellular fractionation of whole cell lysates offers a means of simplifying protein mixtures, potentially permitting greater depth of proteomic analysis. Here we compare proteins identified from pancreatic duct cells (PaDC) following organelle enrichment to those identified from PaDC whole cell lysates to determine if the additional procedures of subcellular fractionation increases proteome coverage. METHODS: We used differential centrifugation to enrich for nuclear, mitochondrial, membrane, and cytosolic proteins. We then compared - via mass spectrometry-based analysis - the number of proteins identified from these four fractions with four biological replicates of PaDC whole cell lysates. RESULTS: We identified similar numbers of proteins among all samples investigated. In total, 1658 non-redundant proteins were identified in the replicate samples, while 2196 were identified in the subcellular fractionation samples, corresponding to a 30% increase. Additionally, we noted that each organelle fraction was in fact enriched with proteins specific to the targeted organelle. CONCLUSIONS: Subcellular fractionation of PaDC resulted in greater proteome coverage compared to PaDC whole cell lysate analysis. Although more labor intensive and time consuming, subcellular fractionation provides greater proteome coverage, and enriches for compartmentalized sub-populations of proteins. Application of this subcellular fractionation strategy allows for a greater depth of proteomic analysis and thus a better understanding of the cellular mechanisms of pancreatic disease.
Biochimica et Biophysica Acta 01/2013; · 4.66 Impact Factor
-
JOP: Journal of the pancreas 01/2013; 14(2):109-11.
-
[show abstract]
[hide abstract]
ABSTRACT: The characterization of the urinary metabolome may yield biomarkers indicative of pancreatitis.
We establish a non-invasive technique to compare urinary metabolic profiles in patients with acute and chronic pancreatitis to healthy controls.
Urine was obtained from healthy controls (HC, n=5), inpatients with mild acute pancreatitis (AP, n=5), and outpatients with chronic pancreatitis (CP, n=5). Proton nuclear magnetic resonance spectra were obtained for each sample. Metabolites were identified and quantified in each spectrum; resulting concentrations were normalized to account for differences in dilution among samples. Kruskal-Wallis test, post-hoc Mann-Whitney U tests, and principal component analysis were performed to identify metabolites that discriminate healthy controls, acute pancreatitis, and chronic pancreatitis.
Sixty metabolites were identified and quantified; five were found to differ significantly (P<0.05) among the three groups. Of these, citrate and adenosine remained significant after validation by random permutation. Principal component analysis demonstrated that healthy control urine samples can be differentiated from patients with chronic pancreatitis or acute pancreatitis; chronic pancreatitis patients could not be distinguished from acute pancreatitis patients.
This metabolomic investigation demonstrates that this non-invasive technique offers insight into the metabolic states of pancreatitis. Although the identified metabolites cannot conclusively be defined as biomarkers of disease, future studies will validate our findings in larger patient cohorts.
JOP: Journal of the pancreas 01/2013; 14(2):161-70.
-
[show abstract]
[hide abstract]
ABSTRACT: In a prior report involving patients with hemoconcentration at admission, those with necrotizing pancreatitis presented significantly earlier than those with interstitial disease suggesting that duration of abdominal pain prior to presentation may have prognostic significance in acute pancreatitis.
The aim of the present study was to determine whether the duration of abdominal pain prior to admission influences the severity of acute pancreatitis.
During a five-year period, all patients presenting directly to our hospital with their first episode of acute pancreatitis were enrolled in a cohort study. We analyzed data obtained from records of all such patients and performed a separate analysis on those with hemoconcentration (hematocrit equal to, or greater than, 44%) at presentation to determine whether duration of abdominal pain prior to presentation was associated with severity of acute pancreatitis. Duration of abdominal pain was categorized as persisting for either less than 12 h or 12 h or more prior to arrival. Prognostic markers of severity included admission hematocrit and blood urea nitrogen (BUN), as well as the development of systemic inflammatory response syndrome (SIRS) during the initial 24 h of hospitalization. Outcome measures included pancreatic necrosis based on contrast-enhanced CT scanning, need for intensive care, length of hospitalization, and death. Radiologic severity of peripancreatic inflammatory changes was assessed within 48 h of admission in accordance with the Balthazar-Ranson scoring system (A-E).
Among a total of 318 patients, there were 62 (19.5%) with hemoconcentration at admission. Among the 318 patients, there was no significant difference in the prevalence of pancreatic necrosis when comparing the less than 12 h group to the 12 h or more group. Among the 62 patients with hemoconcentration, those admitted within 12 h compared to those admitted 12 h or more following the onset of abdominal pain had an increased radiologic severity of acute pancreatitis (Balthazar-Ranson grade D or E: 83.3% vs. 40.0%; P=0.006) and an increased prevalence of pancreatic necrosis (21.1% vs. 2.3%; P=0.028).
Duration of abdominal pain prior to admission impacts the severity of acute pancreatitis only among patients with hemoconcentration at presentation.
JOP: Journal of the pancreas 01/2013; 14(2):171-5.
-
[show abstract]
[hide abstract]
ABSTRACT: We have shown previously that trichloroacetic acid precipitation is an effective method of protein extraction from pancreatic fluid for downstream biomarker discovery, compared to other common extraction methods tested.
We aim to assess the utility of ultracentrifugation as an alternative method of protein extraction from pancreatic fluid.
Proteins extracted from trichloroacetic acid- and ultracentrifugation-precipitated pancreatic fluid were identified using mass spectrometry techniques (in-gel tryptic digestion followed by liquid chromatography-tandem mass spectrometry; GeLC-MS/MS). Data were analyzed using Proteome Discoverer and Scaffold 3.
This is a proteomic analysis experiment of endoscopically collected fluid in an academic center.
The study population included adult patients referred to the Center for Pancreatic Disease at Brigham and Women's Hospital, Boston, MA, USA for the evaluation of abdominal pain and gastrointestinal symptoms.
Secretin-stimulated pancreatic fluid was collected as standard of care for the evaluation of abdominal pain and gastrointestinal symptoms.
We compared proteins identified via standard trichloroacetic acid precipitation and this alternative ultracentrifugation strategy.
A subset of pancreatic fluid proteins was identified via the ultracentrifugation method. Of these proteins, similar numbers were obtained from fully tryptic or semi-tryptic database searching. Proteins identified in the ultracentrifugation-precipitated samples included previously identified biomarker candidates of chronic pancreatitis.
This alternative ultracentrifugation strategy requires less time and fewer handling procedures than standard trichloroacetic acid precipitation, at the expense of higher sample volume. As such, this method is well suited for targeted assays (i.e., dot blotting or targeted mass spectrometry) if the protein of interest is among those readily identified by ultracentrifugation-promoted precipitation.
JOP: Journal of the pancreas 01/2013; 14(2):176-86.
-
[show abstract]
[hide abstract]
ABSTRACT: To compare pancreatic duct cell function in smokers (current and past) and never smokers by measurement of secretin-stimulated peak bicarbonate concentration ([HCO3-]) in endoscopic collected pancreatic fluid (PF).
This retrospective study was cross-sectional in design, recording demographic information (age, gender, etc.), smoking status (former, current, never), alcohol intake, clinical data (imaging, endoscopy), and laboratory results (peak PF [HCO3-]) from subjects evaluated for pancreatic disease at a tertiary pancreas center. Univariate and multivariate statistical analysis (SAS Version 9.2, Cary, NC, USA) was performed to assess the relationship between cigarette smoking and secretin-stimulated pancreatic fluid bicarbonate concentration.
A total of 131 subjects underwent pancreatic fluid collection (endoscopic pancreatic function test, ePFT) for bicarbonate analysis: 25.2% (33 out of 131) past smokers, 31.3% (41 out of 131) current smokers, and 43.5% (57 out of 131) were never smokers. Measures of Association: The mean peak PF [HCO3-] in never smokers (81.3±18.5 mEq/L) was statistically higher (indicating better duct cell function) when compared to past smokers (66.8±24.7 mEq/L, P=0.005) and current smokers (70.0±20.2 mEq/L, P=0.005). However, the mean peak [HCO3-] in past smokers was not statistically different from that in current smokers (P=0.575), and therefore, the two smoking groups were combined to form a single "smokers cohort". When compared to the never smokers, the smokers cohort was older (P=0.037) and had a greater proportion of subjects with definite chronic pancreatitis imaging (P=0.010), alcohol consumption ≥20 g/day (P=0.012), and abnormal peak PF [HCO3-] (P<0.001). Risk-Based Estimates: Cigarette smoking (risk ratio, RR: 2.2, 95% CI: 1.3-3.5; P<0.001), diagnosis of definite chronic pancreatitis imaging (RR: 2.2, 95% CI: 1.6-3.2; P<0.001) and alcohol consumption ≥20 g/day (RR: 1.6, 95% CI: 1.1-2.4; P=0.033) were all associated with low mean peak PF [HCO3-] (indicating duct cell secretory dysfunction). Multivariate Analysis: Smoking (odds ratio, OR: 3.8, 95% CI: 1.6-9.1; P=0.003) and definite chronic pancreatitis imaging (OR: 5.7, 95% CI: 2.2-14.8; P<0.001) were determined to be independent predictors of low peak PF [HCO3-], controlling for age, gender, and alcohol intake. Furthermore there was no interaction between smoking status and alcohol intake in predicting duct cell dysfunction (P=0.571).
Measurement of pancreatic fluid bicarbonate in smokers reveals that cigarette smoking (past and current) is an independent risk factor for pancreatic duct cell secretory dysfunction (low PF [HCO3-]). Furthermore, the risk of duct cell dysfunction in subjects who smoked was approximately twice the risk (RR: 2.2) in never smokers. Further in depth, translational research approaches to pancreatic fluid analysis may help unravel mechanisms of cigarette smoking induced pancreatic duct cell injury.
JOP: Journal of the pancreas 01/2013; 14(1):31-8.
-
[show abstract]
[hide abstract]
ABSTRACT: BACKGROUND AND OBJECTIVE: The Atlanta classification of acute pancreatitis enabled standardised reporting of research and aided communication between clinicians. Deficiencies identified and improved understanding of the disease make a revision necessary. METHODS: A web-based consultation was undertaken in 2007 to ensure wide participation of pancreatologists. After an initial meeting, the Working Group sent a draft document to 11 national and international pancreatic associations. This working draft was forwarded to all members. Revisions were made in response to comments, and the web-based consultation was repeated three times. The final consensus was reviewed, and only statements based on published evidence were retained. RESULTS: The revised classification of acute pancreatitis identified two phases of the disease: early and late. Severity is classified as mild, moderate or severe. Mild acute pancreatitis, the most common form, has no organ failure, local or systemic complications and usually resolves in the first week. Moderately severe acute pancreatitis is defined by the presence of transient organ failure, local complications or exacerbation of co-morbid disease. Severe acute pancreatitis is defined by persistent organ failure, that is, organ failure >48 h. Local complications are peripancreatic fluid collections, pancreatic and peripancreatic necrosis (sterile or infected), pseudocyst and walled-off necrosis (sterile or infected). We present a standardised template for reporting CT images. CONCLUSIONS: This international, web-based consensus provides clear definitions to classify acute pancreatitis using easily identified clinical and radiologic criteria. The wide consultation among pancreatologists to reach this consensus should encourage widespread adoption.
Gut 10/2012; · 10.11 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Diagnosis of pancreatic cystic neoplasms remains problematic. We hypothesize that inflammatory mediator proteins in pancreatic cyst fluid can differentiate branch duct intraductal papillary mucinous neoplasms (BD-IPMNs) and pancreatic inflammatory cysts. We aim to 1) detect inflammatory mediator proteins (IMPs) using a multiplexed IMP-targeted microarray in pancreatic cyst fluid obtained during endoscopic ultrasound fine needle aspiration (EUS-FNA) and 2) compare IMP profiles in pancreatic cyst fluid from BD-IPMNs and inflammatory cysts. Pancreatic cyst fluid from ten patients (5 BD-IPMN and 5 inflammatory cysts) was obtained by EUS-FNA and analyzed directly with a multiplexed microarray assay to determine concentrations of 89 IMPs. Statistical analysis was performed using non-parametric methods.
Eighty-three of the 89 assayed IMPs were detected in at least one of the 10 patient samples. Seven IMPs were detected in BD-IPMN but not inflammatory cysts, while eleven IMPs were identified in inflammatory cysts but not BD-IPMN. Notably, granulocyte-macrophage colony-stimulating factor (GM-CSF) expression was present in all five inflammatory cyst samples. Hepatocyte growth factor (HGF) was present in significantly higher concentrations in inflammatory cysts compared to BD-IPMN.
Our exploratory analysis reveals that GM-CSF and HGF in EUS-FNA-collected pancreatic cyst fluid can distinguish between BD-IPMN and inflammatory cyst. Coupling microarray molecular techniques to EUS-FNA may represent a major step forward to our understanding complex pancreatic disease.
Journal of immunological methods 06/2012; 382(1-2):142-9. · 2.35 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Abstract: Several prior studies have suggested that 80% of deaths in acute pancreatitis occur late as a result of pan-creatic infection.
Others have suggested that approx half of deaths occur early as a result of multisystem organ failure. The aim of the present
study was to determine the timing of mortality of acute pancreatitis at a large tertiary-care hospital in the United States.
Methods: Patients with a diagnosis of acute pancreatitis (ICD-9 code 577.0) admitted to Brigham and Women’s Hospital from October
1, 1982 to June 30, 1995 were retrospectively studied to determine total mortality, frequency of early vs late deaths, and
clinical features of patients with early (≤14 d after admission) or late deaths (>14 d after admission).
Results: The overall mortality of acute pancreatitis was 2.1% (17 deaths among 805 patients). Eight deaths (47%) occurred within the
first 14 d of hospitalization (median d 8, range 1–11 d), whereas 9 occurred after 14 d (median d 56, range 19–81). Early
deaths resulted primarily from organ failure. Late deaths occurred postoperatively in 8 patients with infected or sterile
necrosis and 1 patient with infected necrosis treated medically.
Conclusion: Approximately half of deaths in acute pancreatitis occur within the first 14 d owing to organ failure and the
remainder of deaths occur later because of complications associated with necrotizing pancreatitis. Improvement in mortality
in the future will require innovative approaches to counteract early organ failure and late complications of necrotizing pancreatitis.
International Journal of Gastrointestinal Cancer 04/2012; 28(2):91-95.
-
[show abstract]
[hide abstract]
ABSTRACT: Chronic pancreatitis is characterized by inflammation, fibrosis, pain, and loss of exocrine function of the pancreas. We aimed to identify differentially expressed proteins in the ePFT-collected pancreatic fluid from individuals with chronic pancreatitis (CP; n = 9) and controls with chronic abdominal pain not associated with the pancreas (NP; n = 9). Using GeLC-MS/MS techniques, we identified a total of 1391 different proteins in 18 pancreatic fluid samples. Of these proteins, 257 and 413 were identified exclusively in the control and chronic pancreatitis cohorts, respectively, and 721 were identified in both cohorts. Spectral counting and statistical analysis thereof revealed an additional 38 and 77 proteins that were up- or down-regulated, respectively, in the pancreatic fluid from individuals with chronic pancreatitis. As expected, gene ontology analysis illustrated that the largest percentage of differentially regulated proteins was secreted/extracellular in origin. In addition, proteins that were down-regulated with statistical significance in the chronic pancreatitis cohort were determined to have biological function of proteases, corresponding to the canonical pancreatic insufficiency associated with chronic pancreatitis. Proteins enriched in the pancreatic fluid of chronic pancreatitis patients had roles in fibrosis, inflammation, and pain, whereas digestive enzymes were significantly less abundant. Our workflow provided a mass spectrometry-based approach for the further study of the pancreatic fluid proteome, which may lead to the discovery potential biomarkers of chronic pancreatitis.
Journal of Proteome Research 03/2012; 11(3):1897-912. · 5.11 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Mass spectrometry-based investigation of clinical samples enables the high-throughput identification of protein biomarkers. We provide an overview of mass spectrometry-based proteomic techniques that are applicable to the investigation of clinical samples. We address sample collection, protein extraction and fractionation, mass spectrometry modalities, and quantitative proteomics. Finally, we examine the limitations and further potential of such technologies. Liquid chromatography fractionation coupled with tandem mass spectrometry is well suited to handle mixtures of hundreds or thousands of proteins. Mass spectrometry-based proteome elucidation can reveal potential biomarkers and aid in the development of hypotheses for downstream investigation of the molecular mechanisms of disease.
The Yale journal of biology and medicine 03/2012; 85(1):59-73.
-
[show abstract]
[hide abstract]
ABSTRACT: FFPE tissue is a standard method of specimen preservation for hospital pathology departments. Formalin-fixed paraffin-embedded tissue banks are a resource of histologically characterized specimens for retrospective biomarker investigation. We aim to establish liquid chromatography coupled with tandem mass spectrometry analysis of FFPE pancreatic tissue as a suitable strategy for the study of the pancreas proteome.
We investigated the proteomic profile of FFPE pancreatic tissue specimens, using liquid chromatography coupled with tandem mass spectrometry, from 9 archived specimens that were histologically classified as normal (n = 3), chronic pancreatitis (n = 3), and pancreatic cancer (n = 3).
We identified 525 nonredundant proteins from 9 specimens. Implementing our filtering criteria, 78, 15, and 21 proteins were identified exclusively in normal, chronic pancreatitis, and pancreatic cancer specimens, respectively. Several proteins were identified exclusively in specimens with no pancreatic disease: spink 1, retinol dehydrogenase, and common pancreatic enzymes. Similarly, proteins were identified exclusively in chronic pancreatitis specimens: collagen α1 (XIV), filamin A, collagen α3 (VI), and SNC73. Proteins identified exclusively in pancreatic cancer included annexin 4A and fibronectin.
We report that differentially expressed proteins can be identified among FFPE tissue specimens originating from individuals with different pancreatic histologic findings. The mass spectrometry-based method used herein has the potential to enhance biomarker discovery and chronic pancreatitis research.
Pancreas 03/2012; 41(2):175-85. · 2.39 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The secretin-stimulated endoscopic pancreatic function test (ePFT) allows for the safe collection of gastroduodenal and pancreatic fluid from the duodenum. We test the hypothesis that these endoscopically collected fluids have different proteomes. As such, we aim to show that the ePFT method can be used to collect fluid enriched in pancreatic proteins to test for pancreatic function.
Gastroduodenal and pancreatic fluid were collected sequentially from chronic pancreatitis patients undergoing an ePFT. Proteins from each fluid type were extracted using previously published optimized methods and subjected to GeLC-MS/MS analysis for protein identification and bioinformatics analysis.
Mass spectrometry analysis identified proteins that were exclusive in either gastroduodenal (46) or pancreatic fluid (234). Subsequent quantitative analysis revealed proteins that were differentially abundant with statistical significance. As expected, proteolytic enzymes and protease inhibitors were among the differentially detected proteins. The proteases pepsinogens and gastrin were enriched in gastroduodenal fluid, while common pancreatic enzymes (e.g., aminopeptidase N, chymotrypsin C, elastase-3A, trypsin, and carboxypeptidase A1, and elastase 2B) were found in greater abundance in pancreatic fluid. Similarly for protease inhibitors, members of the cystatin family were exclusive to gastroduodenal fluid, while serpins A11, B4, and D1 were exclusive to pancreatic fluid.
We have shown that ePFT collection coupled with mass spectrometry can be used to identify differentially detected proteins in gastroduodenal and pancreatic fluids. The data obtained using GeLC-MS/MS techniques provide further evidence supporting the feasibility of using ePFT-collected fluid to study specific diseases of the upper gastrointestinal tract, such as chronic pancreatitis.
Clinical and translational gastroenterology. 01/2012; 3:e14.
-
[show abstract]
[hide abstract]
ABSTRACT: Background. Differentiating branch duct from mixed intraductal papillary mucinous neoplasm (BD-IPMN) is problematic, but clinically important as mixed IPMNs are managed surgically, while some BD-IPMN may be followed. Inflammatory mediator proteins (IMPs) have been implicated in acute and chronic inflammatory and malignant pancreatic diseases. Aim. To compare IMP profile of pancreatic cyst fluid collected endoscopically from BD-IPMN and mixed IPMN. Methods. Pancreatic cyst fluid from ten patients (5 BD-IPMN and 5 mixed IPMN) was collected by endoscopic ultrasound-guided fine needle aspiration or endoscopic retrograde cholangiopancreatography. Concentrations of 89 IMPs in these samples were determined using a multiplexed bead-based microarray protein assay and compared between BD-IPMN and mixed IPMN. Results. Eighty-six of 89 IMPs were detected in at least one of the 10 samples. Fourteen IMPs were detected only in mixed IPMN, while none were only in BD-IPMN. Of these, TGF-β1 was most prevalent, present in 3 of 5 mixed IPMNs. Seventy-two IMPs were detected in both BD-IPMN and mixed IPMNs. Of these, only G-CSF (P < 0.05) was present in higher concentrations in mixed IPMNs. Conclusion. TGF-β1 and G-CSF detected in endoscopically collected pancreatic cyst fluid are potential diagnostic biomarkers capable of distinguishing mixed IPMN from BD-IPMN.
Gastroenterology Research and Practice 01/2012; 2012:247309. · 0.98 Impact Factor
