Distribution of α-synuclein in normal human jejunum and its relations with the chemosensory and neuroendocrine system.

Alpha-synuclein (α-syn) is a presynaptic neuronal protein and its structural alterations play an important role in the pathogenesis of neurodegenerative diseases, such as Parkinson's disease (PD). It has been originally described in the brain and aggregated α-syn has also been found in the peripheral nerves including the enteric nervous system (ENS) of PD patients. ENS is a network of neurons and glia found in the gut wall which controls gastrointestinal function independently from the central nervous system. Moreover, two types of epithelial cells are crucial in the creation of an interface between the lumen and the ENS: they are the tuft cells and the enteroendocrine cells (EECs). In addition, the abundant enteric glial cells (EGCs) in the intestinal mucosa play a key role in controlling the intestinal epithelial barrier. Our aim was to localize and characterize the presence of α-syn in the normal human jejunal wall. Surgical specimens of proximal jejunum were collected from patients submitted to pancreaticoduodenectomy and intestinal sections underwent immunohistochemical procedure. Alpha-syn has been found both at the level of ENS and the epithelial cells. To characterize α-syn immunoreactive epithelial cells, we used markers such as choline acetyltransferase (ChAT), useful for the identification of tuft cells. Then we evaluated the co-presence of α-syn with serotonin (5-HT), expressed in EECs. Finally, we used the low-affinity nerve growth factor receptor (p75NTR), to detect peripheral EGCs. The presence of α-syn has been demonstrated in EECs, but not in the tuft cells. Additionally, p75NTR has been highlighted in EECs of the mucosal layer and co-localized with α-syn in EECs but not with ChAT-positive cells. These findings suggest that α-syn could play a possible role in synaptic transmission of the ENS and may contribute to maintain the integrity of the epithelial barrier of the small intestine through EECs.

PIVKA-II: A biomarker for diagnosing and monitoring patients with pancreatic adenocarcinoma.

BACKGROUND: Pancreatic adenocarcinoma (PDAC) is an incurable cancer without adequate tumor markers. Our previous study has showed a better diagnostic performance of Protein Induced by Vitamin K Absence II (PIVKA-II) compared to currently used PDAC biomarkers. To corroborate our previous data with a larger sample size and to assess a possible role of PIVKA-II in predicting surgical success. Additionally, to further evaluate the hypothesis of a direct PIVKA-II production by PDAC cells, we examined PIVKA-II tissue expression in a case of PDAC using immunofluorescence. METHODS: We enrolled 76 newly diagnosed PDAC patients and selected 11 patients to determine PIVKA-II levels also after surgical resection. An immunofluorescence (IF) study of PIVKA-II tissue expression was carried out in one of them. PIVKA-II serum values were measured by chemiluminescent enzyme immunoassay method (CLEIA) on LUMIPULSE G1200 (Fujirebio-Europe, Belgium). RESULTS: PIVKA-II serum levels were above the cut-off at baseline in 71 patients (94%) with a median value of 464 mAU/Ml (range 27-40783 mAU/mL); the sensitivity and specificity were 78.67% and 90.67% respectively. Patients with pre-operative PIVKA-II positivity showed a significant decrease (P < 0.015) of median PIVKA-II serum concentrations after surgery: 820 (91-40783) mAU/mL at diagnosis vs 123 (31-4666) mAU/mL post-operatively. IF assay on PDAC sections demonstrated PIVKA-II expression in cancer cells. CONCLUSION: These data are the first showing a decreased PIVKA-II serum levels after surgery in PDAC patients and reporting PIVKA-II expression in PDAC tissue. Further studies are needed to confirm these findings and to determine PIVKA-II usefulness in diagnosing and monitoring PDAC patients.

Pancreatic ductal adenocarcinoma and distal cholangiocarcinoma: a proposal of preoperative diagnostic score for differential diagnosis.

PURPOSE: The differential diagnosis between primary adenocarcinoma of the pancreas head and distal cholangiocarcinoma remains a clinical challenge. Recent studies have shown important differences in terms of survival between these tumors. Therefore, different treatments should be considered, but the preoperative histological diagnosis is still difficult. Aim of this study is to create a preoperative diagnostic score for differential diagnosis between primary pancreatic adenocarcinoma and primary distal cholangiocarcinoma. METHODS: One hundred eighty consecutive patients who underwent pancreaticoduodenectomy at Sapienza University of Rome from January 2010 to December 2019 were retrospectively analyzed. Inclusion criteria were pancreatic or biliary histologic origin obtained by definitive postoperative histological examination. Exclusion criteria were diagnosis of ampullary carcinoma, non-ampullary duodenal adenocarcinoma, pancreatic metastasis, and benign disease. One hundred one patients were considered eligible for the retrospective study. Preoperative biological, clinical, and radiological parameters were considered. RESULTS: CRP > 10 mg/dL (p = 0.001), modified Glasgow Prognostic Score 2 (p = 0.002), albumin < 35 g/L (p = 0.05), CA 19-9 > 230 U/mL (p = 0.001), and Wirsung diameter > 3 mm (p < 0.001) were significant at univariate logistic analysis. Multivariate logistic analysis has shown that parameters independently associated with primary pancreatic adenocarcinoma were CRP > 10 mg/dL (p = 0.012), CA 19-9 > 230 U/mL (p = 0.043), and diameter of the Wirsung > 3 mm (p = 0.005). Through these parameters, a diagnostic score has been developed to predict a primary pancreatic adenocarcinoma when > 1 and a primary distal cholangiocarcinoma when < 1. CONCLUSION: This feasible and low-cost diagnostic score could have a potential impact to differentiate pancreatic cancer histologic origin and to improve target therapeutic strategy.

A Prognostic Score for Predicting Survival in Patients With Pancreatic Head Adenocarcinoma and Distal Cholangiocarcinoma.

BACKGROUND/AIM: Survival of patients with pancreatic cancer remains poor despite improvements in therapeutic strategies. This study aims to create a novel preoperative score to predict prognosis in patients with tumors of the pancreaticobiliary head. PATIENTS AND METHODS: Data on 190 patients who underwent to pancreaticoduodenectomy at Sapienza University of Rome from January 2010 to December 2018 were retrospectively analyzed. After exclusion criteria, 101 patients were considered eligible for retrospective study. Preoperative biological, clinical and radiological parameters were considered. RESULTS: Pancreatic ductal adenocarcinoma [hazard ratio (HR)=1.995, 95% confidence intervaI (CI)=1.1-3.3; p=0.01], carbohydrate antigen 19.9 (CA 19.9) >230 U/ml (HR=2.414, 95% CI=2.4-1.5, p<0.0001) and Wirsung duct diameter >3 mm (HR=1.592, 95% CI=1.5-0.9; p=0.08) were the only parameters associated with poor prognosis. Through these parameters, a prognostic score (PHT score) was developed which predicted worst survival when exceeding 2 and better survival when ≤2. CONCLUSION: The PHT score may have a potential impact on predicting overall survival and consequently modulate the timing and type of treatment (up-front surgery vs. neoadjuvant therapy) patients are offered.

Genetically driven CD39 expression shapes human tumor-infiltrating CD8+ T-cell functions.

In our study, we investigated the role of CD39 on tumor-infiltrating CD8+ T lymphocytes (CD8+ TILs) in colorectal, head and neck and pancreatic cancers. Partially confirming recent observations correlating the CD39 expression with T-cell exhaustion, we demonstrated a divergent functional activity in CD39+ CD8+ TILs. On the one hand, CD39+ CD8+ TILs (as compared to their CD39- counterparts) produced significantly lower IFN-γ and IL-2 amounts, expressed higher PD-1, and inversely correlated with perforin and granzyme B expression. On the other, they displayed a significantly higher proliferative capacity ex vivo that was inversely correlated with the PD-1 expression. Therefore, CD39+ CD8+ TILs, including those co-expressing the CD103 (a marker of T resident memory [TRM] cells), were defined as partially dysfunctional T cells that correlate with tumor patients with initial progression stages. Interestingly, our results identified for the first time a single nucleotide polymorphism (SNP rs10748643 A>G), as a genetic factor associated with CD39 expression in CD8+ TILs. Finally, we demonstrated that compounds inhibiting CD39-related ATPases improved CD39+ CD8+ T-cell effector function ex vivo, and that CD39+ CD8+ TILs displayed effective suppression function in vitro. Overall these data suggest that the SNP analysis may represent a suitable predictor of CD39+ CD8+ T-cell expression in cancer patients, and propose the modulation of CD39 as a new strategy to restore partially exhausted CD8+ TILs.

Intrapancreatic accessory spleen false positive to 68Ga-Dotatoc: case report and literature review.

BACKGROUND: Intrapancreatic accessory spleen (IPAS) is an uncommon finding of pancreatic mass. Differential diagnosis with pancreatic tumor, especially with non-functional neuroendocrine tumor (NF-NET), may be very hard and sometimes it entails unnecessary surgery. A combination of CT scan, MRI, and nuclear medicine can confirm the diagnosis of IPAS. 68-Ga-Dotatoc PET/CT is the gold standard in NET diagnosis and it can allow to distinguish between IPAS and NET. CASE PRESENTATION: A 69-year-old man was admitted to our hospital for an incidental nodule in the tail of the pancreas with focal uptake of 68-Ga-dotatate at PET/CT. NET was suspected and open distal splenopancreatectomy was performed. Pathologic examination revealed an IPAS. CONCLUSION: This is the second IPAS case in which a positive 68Ga-Dotatoc uptake led to a false diagnosis of pancreatic NET. Here is a proposal of a literature review.

A systematic review on the use of topical hemostats in trauma and emergency surgery.

BACKGROUND: A wide variety of hemostats are available as adjunctive measures to improve hemostasis during surgical procedures if residual bleeding persists despite correct application of conventional methods for hemorrhage control. Some are considered active agents, since they contain fibrinogen and thrombin and actively participate at the end of the coagulation cascade to form a fibrin clot, whereas others to be effective require an intact coagulation system. The aim of this study is to provide an evidence-based approach to correctly select the available agents to help physicians to use the most appropriate hemostat according to the clinical setting, surgical problem and patient's coagulation status. METHODS: The literature from 2000 to 2016 was systematically screened according to PRISMA [Preferred Reporting Items for Systematic Reviews and Meta-Analyses] protocol. Sixty-six articles were reviewed by a panel of experts to assign grade of recommendation (GoR) and level of evidence (LoE) using the GRADE [Grading of Recommendations Assessment, Development and Evaluation] system, and a national meeting was held. RESULTS: Fibrin adhesives, in liquid form (fibrin glues) or with stiff collagen fleece (fibrin patch) are effective in the presence of spontaneous or drug-induced coagulation disorders. Mechanical hemostats should be preferred in patients who have an intact coagulation system. Sealants are effective, irrespective of patient's coagulation status, to improve control of residual oozing. Hemostatic dressings represent a valuable option in case of external hemorrhage at junctional sites or when tourniquets are impractical or ineffective. CONCLUSIONS: Local hemostatic agents are dissimilar products with different indications. A knowledge of the properties of each single agent should be in the armamentarium of acute care surgeons in order to select the appropriate product in different clinical conditions.

Wnt3a/ß-Catenin Signaling Conditions Differentiation of Partially Exhausted T-effector Cells in Human Cancers.

In this study, we investigated the role of the Wnt/ß-catenin signaling pathway in antitumor immune responses. We report that the concentration of secreted Wnt3a was significantly higher in conditioned medium from tumor or nontumor tissues obtained from all hepatocellular carcinoma or colorectal cancer patients tested, than in serum of healthy donors or patients. In addition, both Wnt3a and ß-catenin were overexpressed by tumor-infiltrating and nontumor-infiltrating CD4+ or CD8+ T cells. The majority of these T cells expressed a dysfunctional effector memory Eomes+T-bet-phenotype that we defined as partially exhausted, because they performed effector functions (in terms of interferon-γ and tumor necrosis factor-α production, as well as CD107a mobilization) despite their PD-1 expression. Wnt3a/ß-catenin signaling in T naïve cells in vitro recapitulated the T-cell setting in vivo Indeed, the differentiation of cultured T naïve cells was arrested, producing cells that resembled the EomeshighT-betlowß-cateninhigh T cells with moderate effector functions that infiltrated tumor and nontumor areas. Wnt3a blockade improved the capacity of T naïve cells to differentiate into effector cells in vitro However, Wnt3a blockade did not affect the function and phenotype of differentiated, partially exhausted, tumor-infiltrating T cells ex vivo Taken together, our data suggest that Wnt3a blockade halts the capacity of Wnt/ß-catenin signaling to inhibit the differentiation of T naïve cells, but it does not restore the dysfunction of differentiated T cells, in the tumor setting. Cancer Immunol Res; 6(8); 941-52. ©2018 AACR.

Evolution of pancreatectomy with en bloc venous resection for pancreatic cancer in Italy. Retrospective cohort study on 425 cases in 10 pancreatic referral units.

INTRODUCTION: The aim of this study is to analyze the evolution of pancreatectomy with venous resection in 10 referral Italian centers in the last 25 years. METHODS: A multicenter database of 425 patients submitted to pancreatectomy with venous resection between 1991 and 2015 was retrospectively analyzed. Patients were classified in 5 periods: 1 (1991-1995); 2 (1996-2000); 3 (2001-2005); 4 (2006-2010); 5 (2011-2015). Indications and outcomes were compared according to the period of surgery. RESULTS: Nineteen patients were operated in period 1, 28 in period 2, 91 in period 3, 140 in period 4, and 147 in period 5. Use of neoadjuvant therapy increased from 0% in period 1 and 2-12.1% in period 5. Postoperative complications ranged from 46.3% to 67.8%, and mortality from 5.3% to 9.2%. Median survival progressively increased, from 6 months in period 1-16 months in period 2, 24 months in period 3 and 4 and 35 months in period 5 (p = 0.004). Period, venous and nodal invasion were significant prognostic factors for survival. CONCLUSION: Management and outcomes of pancreatectomy with venous resection have evolved in the last 25 years in Italy. Improvement in patients' multidisciplinary management has lead to significant improvement of median survival.

Myogenic oxidative imbalance interferes with antral motility in obese subjects.

BACKGROUND: Obesity is characterized by a systemic low-grade chronic inflammatory oxidative condition that affects vascular and cardiac smooth muscle relaxation. In human antrum, relaxation is mediated by vasoactive intestinal peptide (VIP) through cAMP and cGMP signaling pathways. A genome-wide association study has demonstrated an association between VIP and obesity. AIM: To evaluate smooth muscle activity in human obese antrum, both in in vitro preparations as well as in vivo. METHODS: Antral muscle strips and cells were isolated from surgical gastric samples from obese and normal weight subjects. Muscle contraction and relaxation, myogenic oxidative stress and inflammatory status were analyzed in vitro. Distal antral motility was evaluated in vivo by magnetic resonance imaging. RESULTS: Obese antral muscle cells showed an oxidative-inflammatory imbalance with overexpression of NLRP3 inflammasome, increased IL-1ß secretion and caspase1-activation, and reduced antioxidant capacity associated with a myogenic motor impairment of VIP-induced relaxation. The intracellular alterations were characterized by a decreased activation of the cAMP-signaling pathway and a decreased expression of eNOS. These in vitro alterations coincided with the hindering of antral motor activity observed in vivo. Apocynin treatment, counteracting oxidative stress, reverted alterations observed in obese antral muscle. CONCLUSION: Antral myogenic activity of obese subjects can be impaired by alterations of signaling pathways induced by oxidative stress.

Prognostic role of nodal ratio, LODDS, pN in patients with pancreatic cancer with venous involvement.

BACKGROUND: The UICC/AJCC TNM staging system classifies lymph nodes as N0 and N1 in pancreatic cancer. Aim of the study is to determine whether the number of examine nodes, the nodal ratio (NR) and the logarithm odds of positive lymph nodes (LODDS) may better stratify the prognosis of patients undergoing pancreatectomy combined with venous resection for pancreatic cancer with venous involvement. METHODS: A multicenter database of 303 patients undergoing pancreatectomy in 9 Italian referral centers was analyzed. The prognostic impact of number of retrieved and examined nodes, NR, LODDS was analyzed and compared with ROC curves analysis, Pearson test, univariate and multivariate analysis. RESULTS: The number of metastatic nodes, pN, the NR and LODDS was significantly correlated with survival at multivariate analyses. The corresponding AUC for the number of metastatic nodes, pN, the NR and LODDS were 0.66, 0.69, 0.63 and 0.65, respectively. The Pearson test showed a significant correlation between the number of retrieved lymph nodes and number of metastatic nodes, pN and the NR. LODDS had the lower coefficient correlation. Concerning N1 patients, the NR, the LODDS and the number of metastatic nodes were able to significantly further stratify survival (p = 0.040; p = 0.046; p = 0.038, respectively). CONCLUSIONS: The number of examined lymph nodes, the NR and LODDS are useful for further prognostic stratification of N1 patients in the setting of pancreatectomy combined with PV/SMV resection. No superiority of one over the others methods was detected.

Skin antisepsis with chlorhexidine versus iodine for the prevention of surgical site infection: A systematic review and meta-analysis.

BACKGROUND: Surgical site infection (SSI) is one of the most frequent health care-associated infections. One of the practices to reduce their incidence is preoperative skin antisepsis. Two of the most commonly active components used are chlorhexidine gluconate and povidone iodine. Of 3 reviews conducted between 2010 and 2012 comparing antiseptics, 2 were in favor of chlorhexidine; however, the latest was unable to draw conclusions. PURPOSE: To verify whether recent evidence supports the hypothesis that chlorhexidine in preoperative antisepsis is more efficient than other antiseptics in reducing SSI rates. PROCEDURES: We conducted a systematic review from 2000-2014 in all languages. The primary end point was SSI incidence and secondary skin bacterial colonization. RESULTS: Nineteen studies were included. Meta-analysis were conducted for comparable studies for both outcomes. The results of the meta-analysis, including all of the studies in which chlorhexidine was compared with iodophor, were in favor of chlorhexidine for both SSI incidence (risk ratio [RR], 0.70; 95% confidence interval [CI], 0.52-0.92) and bacterial skin colonization (RR, 0.45; 95% CI, 0.36-0.55). CONCLUSIONS: There is moderate-quality evidence supporting the use of chlorhexidine for preoperative skin antisepsis and high-quality evidence that the use of chlorhexidine is associated with fewer positive skin cultures. Further rigorous trials will be welcomed to attain stronger evidence as to the best antiseptic to be used before surgery.

Regulatory T cells with multiple suppressive and potentially pro-tumor activities accumulate in human colorectal cancer.

Tregs can contribute to tumor progression by suppressing antitumor immunity. Exceptionally, in human colorectal cancer (CRC), Tregs are thought to exert beneficial roles in controlling pro-tumor chronic inflammation. The goal of our study was to characterize CRC-infiltrating Tregs at multiple levels, by phenotypical, molecular and functional evaluation of Tregs from the tumor site, compared to non-tumoral mucosa and peripheral blood of CRC patients. The frequency of Tregs was higher in mucosa than in blood, and further significantly increased in tumor. Ex vivo, those Tregs suppressed the proliferation of tumor-infiltrating CD8(+) and CD4(+) T cells. A differential compartmentalization was detected between Helios(high) and Helios(low) Treg subsets (thymus-derived versus peripherally induced): while Helios(low) Tregs were enriched in both sites, only Helios(high) Tregs accumulated significantly and specifically in tumors, displayed a highly demethylated TSDR region and contained high proportions of cells expressing CD39 and OX40, markers of activation and suppression. Besides the suppression of T cells, Tregs may contribute to CRC progression also through releasing IL-17, or differentiating into Tfr cells that potentially antagonize a protective Tfh response, events that were both detected in tumor-associated Tregs. Overall, our data indicate that Treg accumulation may contribute through multiple mechanisms to CRC establishment and progression.

Clinical strategies for the management of intestinal obstruction and pseudo-obstruction. A Delphi Consensus study of SICUT (Società Italiana di Chirurgia d'Urgenza e del Trauma).

BACKGROUND: Intestinal obstructions/pseudo-obstruction of the small/large bowel are frequent conditions but their management could be challenging. Moreover, a general agreement in this field is currently lacking, thus SICUT Society designed a consensus study aimed to define their optimal workout. METHODS: The Delphi methodology was used to reach consensus among 47 Italian surgical experts in two study rounds. Consensus was defined as an agreement of 75.0% or greater. Four main topic areas included nosology, diagnosis, management and treatment. RESULTS: A bowel obstruction was defined as an obstacle to the progression of intestinal contents and fluids generally beginning with a sudden onset. The panel identified four major criteria of diagnosis including absence of flatus, presence of >3.5 cm ileal levels or >6 cm colon dilatation and abdominal distension. Panel also recommended a surgical admission, a multidisciplinary approach, and a gastrografin swallow for patients presenting occlusions. Criteria for immediate surgery included: presence of strangulated hernia, a >10 cm cecal dilatation, signs of vascular pedicles obstructions and persistence of metabolic acidosis. Moreover, rules for non-operative management (to be conducted for maximum 72 hours) included a naso-gastric drainage placement and clinical and laboratory controls each 12 hours. Non-operative treatment should be suspended if any suspects of intra-abdominal complications, high level of lactates, leukocytosis (>18.000/mm3 or Neutrophils >85%) or a doubling of creatinine level comparing admission. Conversely, consensus was not reached regarding the exact timing of CT scan and the appropriateness of colonic stenting. CONCLUSIONS: This consensus is in line with current international strategies and guidelines, and it could be a useful tool in the safe basic daily management of these common and peculiar diseases. KEY WORDS: Delphi study, Intestinal obstruction, Large bowel obstruction, Pseudo-obstruction, Small bowel.

Pancreatectomy with Mesenteric and Portal Vein Resection for Borderline Resectable Pancreatic Cancer: Multicenter Study of 406 Patients.

PURPOSE: The role of pancreatectomy with en bloc venous resection and the prognostic impact of pathological venous invasion are still debated. The authors analyzed perioperative, survival results, and prognostic factors of pancreatectomy with en bloc portal (PV) or superior mesenteric vein (SMV) resection for borderline resectable pancreatic carcinoma, focusing on predictive factors of histological venous invasion and its prognostic role. METHODS: A multicenter database of 406 patients submitted to pancreatectomy with en bloc SMV and/or PV resection for pancreatic adenocarcinoma was analyzed retrospectively. Univariate and multivariate analysis of factors related to histological venous invasion were performed using logistic regression model. Prognostic factors were analyzed with log-rank test and multivariate proportional hazard regression analysis. RESULTS: Complications occurred in 51.9 % of patients and postoperative death in 7.1 %. Histological invasion of the resected vein was confirmed in 56.7 % of specimens. Five-year survival was 24.4 % with median survival of 24 months. Vein invasion at preoperative computed tomography (CT), N status, number of metastatic lymph nodes, preoperative serum albumin were related to pathological venous invasion at univariate analysis, and vein invasion at CT was independently related to venous invasion at multivariate analysis. Use of preoperative biliary drain was significantly associated with postoperative complications. Multivariate proportional hazard regression analysis demonstrated a significant correlation between overall survival and histological venous invasion and administration of adjuvant therapy. CONCLUSIONS: This study identifies predictive factors of pathological venous invasion and prognostic factors for overall survival, including pathological venous invasion, which may help with patients' selection for different treatment protocols.

Extrathyroidal Calcitonin Secreting Tumors: Pancreatic Neuroendocrine Tumors in Patients With Multinodular Goiter: Two Case Reports.

Calcitonin is the hallmark of medullary thyroid carcinoma. However, extrathyroidal neuroendocrine tumors can also release calcitonin.We report 2 cases of calcitonin-secreting pancreatic tumors found in asymptomatic patients with thyroid nodules referred to our center within 11 months.Case 1: A man initially referred for thyroid nodule characterization was found to have hypercalcitoninemia (>200 pg/mL) during non-neoplastic fine-needle aspiration.Case 2: A woman evaluated for liver metastasis was found to have hypercalcitoninemia and multinodular goiter.Our research emphasizes that marked hypercalcitoninemia in the presence of thyroid nodules is not necessarily due to medullary thyroid carcinoma; awareness of this could avoid unnecessary thyroidectomy. The lack of specific symptoms related to hypercalcitoninemia may be the reason that the prevalence of calcitonin-secreting pancreatic tumors is underestimated.

Endocrine cells distribution in human proximal small intestine: an immunohistochemical and morphometrical study.

Atrophy of the pancreatic remnant after pancreaticoduodenectomy might be consequent to dereg- ulation of pancreatic endocrine stimuli after duodenal removal. Relative technical surgical solu- tion could be the anastomosis of the 1st jejunal loop to the stomach and the 2nd to the pancreatic stump. Data on the distribution of endocrine cells within the proximal intestine might represent the lacking tile of the problem. Our aims were to investigate the distribution pattern of seroto- nin, cholecystokinin and secretin cells in the duodenum, the 1st and 2nd jejunal loops of humans. Bowel specimens of ten patients submitted to pancreaticoduodenectomy were collected; immuno- histochemical reactions and morphometric analyses were performed. A general ab-oral decrease of enteroendocrine cells was found. The rate of serotonin cells showed a significant 30.67±8.13% reduction starting from the 1s' jejunal loop versus duodenum. The rate of both cholecystokinin and secretin cells in the duodenum was superimposable to that in the 1st jejunal loop, with a sig- nificant 62.88±4.80% loss of cholecystokinin and 39.5±9.31% of secretin cells in the 2nd loop. After removal of duodenum, preservation of the 1st jejunal loop could impact the function of pancreatic remnant maintaining the physiological enteroendocrine stimulus for pancreatic secretion that can compensate, at least in part for the abolished duodenal hormonal release.

The "meso" of the rectum and the "meso" of the pancreas: similar terms but distinct concepts in surgical oncology.

A correspondence between the "meso" of the rectum and of the pancreas has recently been reported. Here we highlight the differences between mesorectum and mesopancreas. Based on anatomical findings from a series of 89 consecutive pancreaticoduodenectomies and 71 consecutive total mesorectal excisions, we observed that in contrast to the mesorectum, the mesopancreas did not have well-defined anatomic boundaries and was continuous and connected through its components with the para-aortic area. In rectal cancer, tumor deposits and nodal involvement could be confined to the mesorectum (i.e., within the mesorectal fascia), whereas in pancreatic carcinoma, tumor deposits and nodal metastases occurred in the boundless mesopancreatic area. Total mesorectal excision was made en bloc with the rectum by dissecting along the mesorectal fascia; this was not the case for mesopancreatic excision since anatomical demarcation of the mesopancreas did not exist. Moreover, the growth pattern of pancreatic cancer showed greater dispersion, which was more prominent at the invasive front of the tumor and could potentially affect the status of the resection margin. These findings indicate that the mesorectum and mesopancreas are completely distinct from the pathological, surgical, and oncological standpoints.