Factors Associated With the Risk of Progression of Low-Risk Branch-Duct Intraductal Papillary Mucinous Neoplasms

IMPORTANCE

Branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) are common pancreatic preneoplastic lesions, but their surveillance is not personalized.

OBJECTIVE

To investigate patient- and cyst-related factors associated with progression into worrisome features (WFs) or high-risk stigmata (HRS) categories of BD-IPMNs.

DESIGN, SETTING, AND PARTICIPANTS

Cyst- and patient-related factors of consecutive BD-IPMNs without WFs or HRS in 540 patients diagnosed from 2009 to 2018 with at least 12 months' surveillance until February 28, 2020, were registered in a 2-center ambispective cohort study in Italy. In a subgroup, the ABO blood group was studied for the first time in this setting.

EXPOSURE

Cyst-related and patients-related factors and ABO blood group.

MAIN OUTCOMES AND MEASURES

The study outcome was the appearance of WFs or HRS according to the 2017 International Association of Pancreatology guidelines. Survival probability was calculated using Kaplan-Meier curve and risk factors identified by Cox proportional hazards regression. ABO blood group was inferred through genotypes with DNA extraction.

RESULTS

Of 540 patients with BD-IPMNs (median age, 66 years [interquartile range, 58.5-72.0 years]; 337 women [62.4%]) undergoing surveillance for a median of 51.5 months (interquartile range, 28-84 months) for 2758 person-years, 130 patients (24.1%) experienced progression. Probability of progression was 3.7% at 1 year, 23.4% at 5 years, and 43.3% at 10 years; 15 patients (2.8%) underwent surgery, 7 patients (1.3%) had malignant histologic findings, and 3 patients (0.56%) died of pancreatic-associated disease. Initial cyst size greater than 15 mm (hazard ratio [HR], 2.05; 95% CI, 1.44-2.91), body mass index greater than 26.4 (HR, 1.72; 95% CI, 1.19-2.50), and heavy smoking (HR, 1.81; 95% CI, 1.14-2.86) were significant independent factors associated with progression risk. The AA blood genotype was also associated with progression risk (HR, 3.49; 95% CI, 1.04-11.71) compared with the OO genotype in the investigated subgroup.

CONCLUSIONS AND RELEVANCE

This analysis of factors associated with progression of BD-IPMNs according to recent guidelines suggests that cyst size alone is not a reliable factor for estimation of progression risk; however, along with other readily available data, size is helpful for planning personalized surveillance of BD-IPMNs.

Needle-knife fistulotomy vs. standard biliary sphincterotomy for choledocholithiasis: common bile duct stone recurrence and complication rate

Background and study aims  With common bile duct (CBD) stones, access to the CBD can be achieved through the papilla orifice followed by standard biliary sphincterotomy (SBS), or through precut fistulotomy (PF) in case of difficult cannulation. The two methods alter papilla anatomy differently, potentially leading to a different rate of stone recurrence. No data have been published on stone recurrence after PF in patients with CBD stones. The aim of this study was to evaluate CBD stone recurrence, reintervention rate after PF versus SBS, and complications. Patients and methods  This was a retrospective single-center cohort study including patients undergoing for the first time endoscopic retrograde cholangiopancreatography (ERCP) for CBD stones with PF in case of failed repeated cannulation attempts, matched for sex/age to patients with SBS randomly extracted from our database. T -test and Fisher's tests were used for continuous and categorical variable comparison. Recurrence probability was calculated with Kaplan-Meier curve. Factors associated with ERCP repetition were evaluated with logistic regression through a Cox's proportional hazards model. Results  Eighty-five patients with PF were included, with 85 matched controls (mean age 68.7 years, 45.9 % males). Overall, patients with PF had the same reintervention rate as those with SBS (14.1 % vs. 12.9 %) with a hazard ratio (HR) of 1.11 (95 % CI 0.49 - 2.50; P  = 0.81), but mean time to reintervention was significantly lower (74.9 ± 74.6 vs. 765.6 ± 961.3 days; P  < 0.0001), with 100 % of stones recurring within the first year in the PF group vs. 54.5 % in the SBS group ( P  = 0.01). The only factor associated with ERCP repetition risk was incomplete CBD clearing. Complications, including pancreatitis, did not differ significantly. Conclusions  The reintervention rate was significantly higher in the short term after PF. Therefore, closer follow-up in the first 6 to 12 months after ERCP might be appropriate for patients underoing PF.

Exocrine pancreatic insufficiency: prevalence, diagnosis, and management

Exocrine pancreatic insufficiency (EPI) is a condition caused by reduced or inappropriate secretion or activity of pancreatic juice and its digestive enzymes, pancreatic lipase in particular. EPI can result in clinical manifestation and biochemical alterations causing reduced quality of life and life-threating complications. EPI is common in pancreatic disorders, where it should be suspected and actively investigated, and in many extrapancreatic conditions. There are various tests available to diagnose EPI, with indirect, noninvasive ones, such as concentration of fecal elastase being more commonly employed. Administration of pancreatic enzymes replacement therapy remains the mainstay of EPI treatment. The present review article will discuss current evidence regarding the prevalence of EPI, the available tests to diagnose it and its treatment.

Correction: Long-term follow-up of low-risk branchduct IPMNs of the pancreas: is main pancreatic duct dilatation the most worrisome feature?

In the HTML version of this paper Pietro Magnoni was incorrectly tagged as the corresponding author. The corresponding author should have been Maria Chiara Petrone. This has now been corrected in the HTML version of the paper.

Long-term follow-up of low-risk branch-duct IPMNs of the pancreas: is main pancreatic duct dilatation the most worrisome feature?

OBJECTIVES

The management of branch-duct IPMN remains controversial due to the relatively low rate of malignant degeneration and the uncertain predictive role of high-risk stigmata (HRS) and worrisome features (WFs) identified by the 2012 International Consensus Guidelines. Our aim was to evaluate the evolution of originally low-risk (Fukuoka-negative) BD-IPMNs during a long follow-up period in order to determine whether the appearance of any clinical or morphological variables may be independently associated with the development of malignancy over time.

METHODS

A prospectively collected database of all patients with BD-IPMN referring to our Institute between 2002 and 2016 was retrospectively analyzed. Univariate and multivariate analysis of association between changes during follow-up, including appearance of HRS/WFs, and development of malignancy (high-grade dysplasia/invasive carcinoma) was performed.

RESULTS

A total of 167 patients were selected for analysis, and seven developed malignant disease (4.2%). During a median follow-up time of 55 months, HRS appeared in only three cases but predicted malignancy with 100% specificity. Worrisome features, on the other hand, appeared in 44 patients (26.3%). Appearance of mural nodules and MPD dilatation >5 mm showed a significant association with malignancy in multivariate analysis (p = 0.004 and p = 0.001, respectively). MPD dilatation in particular proved to be the strongest independent risk factor for development of malignancy (OR = 24.5).

CONCLUSIONS

The risk of pancreatic malignancy in this population is low but definite. The presence of major WFs, and especially MPD dilatation, should prompt a tighter follow-up with EUS and a valid cytological analysis whenever feasible.

Genome-wide analysis of Saccharomyces cerevisiae identifies cellular processes affecting intracellular aggregation of Alzheimer's amyloid-β42: importance of lipid homeostasis

Amyloid-β (Aβ)-containing plaques are a major neuropathological feature of Alzheimer's disease (AD). The two major isoforms of Aβ peptide associated with AD are Aβ40 and Aβ42, of which the latter is highly prone to aggregation. Increased presence and aggregation of intracellular Aβ42 peptides is an early event in AD progression. Improved understanding of cellular processes affecting Aβ42 aggregation may have implications for development of therapeutic strategies. Aβ42 fused to green fluorescent protein (Aβ42-GFP) was expressed in ∼4600 mutants of a Saccharomyces cerevisiae genome-wide deletion library to identify proteins and cellular processes affecting intracellular Aβ42 aggregation by assessing the fluorescence of Aβ42-GFP. This screening identified 110 mutants exhibiting intense Aβ42-GFP-associated fluorescence. Four major cellular processes were overrepresented in the data set, including phospholipid homeostasis. Disruption of phosphatidylcholine, phosphatidylserine, and/or phosphatidylethanolamine metabolism had a major effect on intracellular Aβ42 aggregation and localization. Confocal microscopy indicated that Aβ42-GFP localization in the phospholipid mutants was juxtaposed to the nucleus, most likely associated with the endoplasmic reticulum (ER)/ER membrane. These data provide a genome-wide indication of cellular processes that affect intracellular Aβ42-GFP aggregation and may have important implications for understanding cellular mechanisms affecting intracellular Aβ42 aggregation and AD disease progression.

Proteomic analysis of a developmentally regulated secretory vesicle

Secretion of spore coat proteins from the prespore secretory vesicles (PSVs) in Dictyostelium discoideum is a signal mediated event that underlies terminal cell differentiation, and represents an important case of developmentally regulated secretion. In order to study the biochemical mechanisms that govern the regulated fusion of the PSVs with the plasma membrane and the subsequent secretion of their cargo, we purified this organelle from prespore cells. Analysis of protein extracts of highly purified PSVs indicated that, in addition to the cargo of structural spore coat proteins, many more proteins are associated with the PSVs. Their identification is paramount to the understanding of the mechanism of regulated secretion in this system. In this study we have taken the first comprehensive proteomic approach to the analysis of an entire, previously uncharacterized, organelle, with the goal of identifying the major proteins associated with the PSVs. We show that in addition to the structural spore coat proteins, the PSVs contain the enzymes needed for proper spore coat assembly (thioredoxin 2 and 3), regulatory proteins which we predict receive and transduce the developmental signal for secretion (rab7 GTPase, PI-3 kinase, NDP kinase and the calcium binding proteins calfumirin-1 and calreticulin) as well as proteins that interact with the cytoskeleton to mediate movement of the PSVs to the plasma membrane (actin binding proteins coactosin and profilin 1). In addition, the results suggest that proteins can play multiple roles in the cell, and that protein function can be dictated in part by subcellular localization. The identification of the PSV proteins is allowing us to develop testable hypotheses about the roles of these proteins within the functional context of developmentally regulated secretion.

Towards an automated approach for protein identification in proteome projects

The development of automated, high throughput technologies for the rapid identification of proteins is essential for large-scale proteome projects. While a degree of automation already exists in some stages of the protein identification process, such as automated acquisition of matrix assisted laser desorption ionisation-time of flight (MALDI-TOF) mass spectra, efficient interfaces between different stages are still lacking. We report the development of a highly automated, integrated system for large scale identification of proteins separated by two-dimensional gel electrophoresis (2-DE), based on peptide mass fingerprinting. A prototype robotic system was used to image and excise 288 protein spots from an amido black stained polyvinylidene difluoride (PVDF) blot. Protein samples were enzymatically digested with a commercial automated liquid handling system. MALDI-TOF mass spectrometry was used to acquire mass spectra automatically, and the data analysed with novel automated peptide mass fingerprinting database interrogation software. Using this highly automated system, we were able to identify 95 proteins on the basis of peptide mass fingerprinting, isoelectric point and molecular weight, in a period of less than ten working days. Advantages, problems, and future developments in robotic excision systems, liquid handling, and automated database interrogation software are discussed.

Extraction of membrane proteins by differential solubilization for separation using two-dimensional gel electrophoresis

We describe the extraction and enrichment of membrane proteins for separation by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) after differential solubilization of an Escherichia coli cell lysate. In a simple three-step sequential solubilization protocol applicable for whole cell lysates, membrane proteins are partitioned from other cellular proteins by their insolubility in solutions conventionally used for isoelectric focusing (IEF). As the first step, Tris-base was used to solubilize many cytosolic proteins. The resultant pellet was then subjected to conventional solubilizing solutions (urea, 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate, dithiothreitol, Tris, carrier ampholytes). Following the completion of this step, 89% of the initial E. coli sample mass was solubilized. Finally, the membrane protein rich pellet was partially solubilized using a combination of urea, thiourea, tributyl phosphine and multiple zwitterionic surfactants. Using N-terminal sequence tagging and peptide mass fingerprinting we have identified 11 membrane proteins from this pellet. Two of these outer membrane proteins (Omp), OmpW and OmpX, have previously been known only as an open reading frame in E. coli, while OmpC, OmpT and OmpTOLC have not previously been identified on a 2-D gel. The prefractionation of an entire cell lysate into multiple fractions, based on solubility, results in simplified protein patterns following 2-D PAGE using broad-range pH 3.5-10 immobilized pH gradients (IPGs). Additional advantages of sample prefractionation are that protein identification and gel matching, for database construction, is a more manageable task, the procedure requires no specialized apparatus, and the sequential extraction is conducted in a single centrifuge tube, minimizing protein loss.

[Conventional and single-use burs. Cavity preparation comparison]

Our work's aim, was to value the wear of conventional and monouse burs, while preparing the cavity. Usually the conventional burs give better technical efficiency, but the monouse ones represent a notable progress both in technology and prevention.

Bilateral accessory digastric muscles

Four aberrant muscles occurring in the submandibular region are described. Accessory digastric muscles were found lying in the submental triangle. All four muscles were attached to the mylohyoid raphe. On one side the anterior muscle ran to the mandible while the posterior muscle reached the hyoid bone. Three of these muscles (the exception being that attached to the mandible) fused with the ipsilateral anterior belly of digastric thus presenting an unusual bilateral arrangement.