Directed Evolution of Glycosyltransferases by a Single-Cell Ultrahigh-Throughput FACS-Based Screening Method.

Engineering of glycosyltransferases (GTs) with desired substrate specificity for the synthesis of complex oligosaccharides has been of great scientific and industrial interest. Here we describe an ultra-high-throughput fluorescence activated cell sorting (FACS) method for the directed evolution of GTs, at the single cell level. This assay relies on the exquisite substrate specificity of lactose permeases (LacY) that are located in the cell membrane, which distinguish selectively the fluorescent glycosylated products from the unreacted substrates. The method described here allows facile screening 106-107 mutants per hour. We demonstrate the application of this technique in the screening of libraries of α1,3-fucosyltransferase.

Glycosyltransferases: Mining, engineering and applications in biosynthesis of glycosylated plant natural products.

UDP-Glycosyltransferases (UGTs) catalyze the transfer of nucleotide-activated sugars to specific acceptors, among which the GT1 family enzymes are well-known for their function in biosynthesis of natural product glycosides. Elucidating GT function represents necessary step in metabolic engineering of aglycone glycosylation to produce drug leads, cosmetics, nutrients and sweeteners. In this review, we systematically summarize the phylogenetic distribution and catalytic diversity of plant GTs. We also discuss recent progress in the identification of novel GT candidates for synthesis of plant natural products (PNPs) using multi-omics technology and deep learning predicted models. We also highlight recent advances in rational design and directed evolution engineering strategies for new or improved GT functions. Finally, we cover recent breakthroughs in the application of GTs for microbial biosynthesis of some representative glycosylated PNPs, including flavonoid glycosides (fisetin 3-O-glycosides, astragalin, scutellarein 7-O-glucoside), terpenoid glycosides (rebaudioside A, ginsenosides) and polyketide glycosides (salidroside, polydatin).

Moxibustion for the treatment of diabetic peripheral neuropathy: A systematic review and meta-analysis following PRISMA guidelines.

BACKGROUND: At present, the effect of western-medicine (WM) therapy to treat diabetic peripheral neuropathy (DPN) is limited. Moxibustion is a representative external treatment in traditional Chinese medicine that has been beneficial to DPN. We aim to systematically assess the efficacy and safety of moxibustion in treating DPN, following PRISMA guidelines. METHODS: Eight electronic databases were searched to acquire information on eligible trials published from inception to June 1, 2019. We included randomized controlled trials (RCTs) applying moxibustion therapy with a minimum of 14-days treatment duration for DPN patients compared with placebo, no intervention, or conventional WM interventions. The primary outcomes in our study include the sensory-nerve conduction velocity (SNCV) and motor-nerve conduction velocity (MNCV). We used the Cochrane Collaboration Risk of Bias tool to assess the methodological quality of eligible RCTs. Statistical analyses were conducted using Review Manager 5.3. Risk ratios (RR) and mean differences (MD) were calculated with a 95% confidence interval (CI). The χ test was applied to assess the heterogeneity. RESULTS: In total, 11 RCTs were included that involved 927 DPN patients. Compared with the control group, there was an increase in median MNCV (MD = 6.26, 95% CI 2.64-9.89, Z = 3.39, P = .0007) and peroneal MNCV (MD = 6.45, 95% CI 5.30-7.61, P < .00001). There was also an increase in median SNCV (MD = 6.64, 95% CI 3.25-10.03, P = .0001) and peroneal SNCV (MD = 3. 57, 95% CI 2.06-5.09, Z = 4.63, P < .00001) in the treatment groups. The treatment groups receiving moxibustion therapy indicated a more significant improvement in total effectiveness rate (RR = 0.25, 95% CI 0.18-0.37, Z = 7.16, P < .00001). Toronto Clinical Scoring System indicated a significant decrease in the treatment groups (MD = -2.12, 95% CI -2.82 to 1.43, P < .00001). Only 1 study reported that treatment groups experienced no adverse reactions. The other 10 studies did not mention adverse events. CONCLUSIONS: Moxibustion therapy may be an effective and safe option for DPN patients but needs to be verified in further rigorous studies.

Qizhijiangtang capsule for the treatment of diabetic kidney disease: A protocol for systematic review and meta-analysis.

BACKGROUNDS: Diabetic kidney disease (DKD) is 1 of the common microvascular complications of diabetes, and the therapeutic effect of modern medicine on DKD is limited. At present, patented Chinese medicine Qizhijiangtang (QZJT) capsule has been widely used in the treatment of DKD. We aim to systematically assess the efficacy and safety of QZJT capsule for the treatment of diabetic kidney disease (DKD). METHODS: Randomized controlled trials of QZJT capsule for DKD treatment will be searched until July 1, 2020, in 7 electronic databases: PubMed, Embase, Cochrane Library, CNKI, Wanfang, VIP, and Chinese Biomedical Literature. Furthermore, additional relevant publications will be manually searched according to reference lists from the resulting publications. The Cochrane risk test from the Cochrane Handbook will be used as a bias tool to evaluate the methodological quality. The clinical efficacy will be the primary outcome, which is based on the changes in symptoms and levels of proteinuria. Review Manager 5.3 will be used to analyze the results. RESULTS AND CONCLUSIONS: Our meta-analysis will provide evidence to the clinical application of QZJT capsule in the treatment of DKD from the 4 aspects including the clinical efficacy, changes in proteinuria, the renal function and level of blood glucose. Meanwhile, the results can also reflect the role of traditional Chinese medicine in the treatment of DKD. PROSPERO REGISTRATION NUMBER: CRD42020153949.

Qidong Yixin Oral Liquid for Viral Myocarditis: A Systematic Review and Meta-Analysis.

OBJECTIVE: This study aimed to evaluate the efficacy and safety of Qidong Yixin (QY) oral liquid in the treatment of viral myocarditis (VMC). METHODS: We searched seven databases for randomized clinical trials on QY for treating VMC. The retrieval period was from database establishment to December 31, 2019. Cochrane risk of bias tool in the Cochrane Handbook was used to assess the methodological quality. Review Manager (RevMan) 5.3 was used to analyze the results. RESULTS: We included 19 studies comprising 2,608 patients, albeit with low methodological quality. Our meta-analysis revealed that combination therapy with QY and western medicine was more effective than western medicine alone (QY vs other Chinese patent medicines: RR = 1.37, 95% Cl: 1.23∼1.52, P < 0.00001; QY + coenzyme Q10 + routine treatment vs coenzyme Q10 + routine treatment: RR = 1.20, 95% Cl: 1.14∼1.27, P < 0.00001; QY + trimetazidine + acyclovir vs trimetazidine + acyclovir: RR = 1.59, 95% Cl: 1.38∼1.83, P < 0.00001; QY + routine treatment vs routine treatment: RR = 1.09, 95% Cl: 1.03∼1.15, P < 0.003). A study on posttreatment myocardial enzyme levels revealed that QY with western medicine downregulated creatine kinase isoenzyme (CK-MB) (QY + antiviral treatment + routine treatment vs antiviral treatment + routine treatment group: MD = -11.28, 95% CI: -13.33∼-9.22, P < 0.00001; QY + routine treatment vs routine treatment: MD = -4.96, 95% CI: -5.56∼-4.32, P < 0.00001), creatine kinase (CK) (MD = -32.10, 95% CI: -35.63∼-28.57, P < 0.00001), and lactate dehydrogenase (LDH) (QY + antiviral treatment + routine treatment vs antiviral treatment + routine treatment: MD = -48.76 95% CI: -58.18∼-39.33, P < 0.00001; QY + routine treatment vs routine treatment: MD = -23.52, 95% CI: -30.10-16.94, P < 0.00001) rather than western medicine alone, with no evidence of aspartate aminotransferase (AST) downregulation on treatment with QY with western medicine (MD = 2.88, 95% CI: -0.95∼6.71, P < 0.00001) in patients. Two studies reported adverse events, indicating that QY is relatively safe. CONCLUSION: Although QY may have potential advantages in treating VMC, they remain unclear owing to the poor methodological quality of most studies. Larger, multicenter, high-quality randomized controlled trials are required to verify the effectiveness of QY.

Banxia Xiexin Decoction Ameliorates t-BHP-Induced Apoptosis in Pancreatic Beta Cells by Activating the PI3K/AKT/FOXO1 Signaling Pathway.

BACKGROUND: Banxia Xiexin Decoction (BXXD) reportedly regulates glycolipid metabolism and inhibits pancreatic ß-cell apoptosis. This study is aimed at investigating the protective effect of BXXD on tert-butyl hydroperoxide- (t-BHP-) induced apoptosis in MIN6 cells and the underlying mechanisms. METHODS: MIN6 cells were preincubated with BXXD or liraglutide (Li) with or without PI3K inhibitor LY294002 (LY) for 12 h, following which t-BHP was added to induce MIN6 cell apoptosis. The protective effects of BXXD on MIN6 cells were evaluated by detecting cell viability and proliferation and glucose-stimulated insulin secretion (GSIS). The antiapoptotic effects were evaluated by Hoechst 33342 staining and terminal deoxynucleotidyl transferase dUTP nick end labeling assay (TUNEL). Malondialdehyde and glutathione peroxidase content and superoxide dismutase activity were measured using commercial kits. The expression of PI3K/AKT/FOXO1 signaling pathway-related signal molecules, and that of apoptotic indicators Bax, P27, and Caspase-3, was quantified using western blotting. RESULTS: Preincubation with BXXD significantly improved t-BHP-induced proliferation inhibition and apoptosis and enhanced GSIS. t-BHP induced the generation of reactive oxygen species and inhibited the activities of antioxidant enzymes, which could be neutralized by pretreatment with BXXD. BXXD promoted the phosphorylation of AKT and FOXO1 in t-BHP-induced MIN6 cells. Moreover, BXXD attenuated the expression of related apoptotic indicators Bax, P27, and Caspase-3. LY abolished these effects of BXXD. CONCLUSION: BXXD protected MIN6 cells against t-BHP-induced apoptosis and improved insulin secretory function through modulation of the PI3K/AKT pathway and the downstream FOXO1, thus suggesting a novel therapeutic approach for type 2 diabetes mellitus (T2DM).

Directed evolution of an α1,3-fucosyltransferase using a single-cell ultrahigh-throughput screening method.

Fucosylated glycoconjugates are involved in a variety of physiological and pathological processes. However, economical production of fucosylated drugs and prebiotic supplements has been hampered by the poor catalytic efficiency of fucosyltransferases. Here, we developed a fluorescence-activated cell sorting system that enables the ultrahigh-throughput screening (>107 mutants/hour) of such enzymes and designed a companion strategy to assess the screening performance of the system. After three rounds of directed evolution, a mutant M32 of the α1,3-FucT from Helicobacter pylori was identified with 6- and 14-fold increases in catalytic efficiency (k cat/K m) for the synthesis of Lewis x and 3'-fucosyllactose, respectively. The structure of the M32 mutant revealed that the S45F mutation generates a clamp-like structure that appears to improve binding of the galactopyranose ring of the acceptor substrate. Moreover, molecular dynamic simulations reveal that helix α5, is more mobile in the M32 mutant, possibly explaining its high fucosylation activity.

Structural Insights into the Broad Substrate Specificity of a Novel Endoglycoceramidase I Belonging to a New Subfamily of GH5 Glycosidases.

Endoglycoceramidases (EGCases) specifically hydrolyze the glycosidic linkage between the oligosaccharide and the ceramide moieties of various glycosphingolipids, and they have received substantial attention in the emerging field of glycosphingolipidology. However, the mechanism regulating the strict substrate specificity of these GH5 glycosidases has not been identified. In this study, we report a novel EGCase I from Rhodococcus equi 103S (103S_EGCase I) with remarkably broad substrate specificity. Based on phylogenetic analyses, the enzyme may represent a new subfamily of GH5 glycosidases. The X-ray crystal structures of 103S_EGCase I alone and in complex with its substrates monosialodihexosylganglioside (GM3) and monosialotetrahexosylganglioside (GM1) enabled us to identify several structural features that may account for its broad specificity. Compared with EGCase II from Rhodococcus sp. M-777 (M777_EGCase II), which possesses strict substrate specificity, 103S_EGCase I possesses a longer α7-helix and a shorter loop 4, which forms a larger substrate-binding pocket that could accommodate more extended oligosaccharides. In addition, loop 2 and loop 8 of the enzyme adopt a more open conformation, which also enlarges the oligosaccharide-binding cavity. Based on this knowledge, a rationally designed experiment was performed to examine the substrate specificity of EGCase II. The truncation of loop 4 in M777_EGCase II increased its activity toward GM1 (163%). Remarkably, the S63G mutant of M777_EGCase II showed a broader substrate spectra and significantly increased activity toward bulky substrates (up to >1370-fold for fucosyl-GM1). Collectively, the results presented here reveal the exquisite substrate recognition mechanism of EGCases and provide an opportunity for further engineering of these enzymes.

Validation of five contemporary prognostication systems for primary pancreatic endocrine neoplasms: results from a single institution experience with 61 surgically treated cases.

BACKGROUND: Presently, several systems for the prognostication of pancreatic endocrine neoplasms (PENs) exist and the most appropriate classification system has not been clearly defined. This study aims to validate the performance of the 2004 World Health Organization (WHO), European Neuroendocrine Tumor Society (ENETS), Memorial Sloan-Kettering Cancer Center (MSKCC), American Joint Committee for Cancer (AJCC) TNM staging and Bilimoria criteria in a cohort of patients with PENs who underwent surgery at a single institution. METHODS: This study is a retrospective review of 61 consecutive patients who underwent surgical treatment for PEN. Actuarial disease-specific survival (DSS) of all 61 patients and recurrence-free survival (RFS) of 53 patients who had curative resection were analysed. RESULTS: On univariate analyses, tumour size ≥50 mm, non-curative resection, lymph node involvement, presence of distant metastases, presence of necrosis, mitotic count ≥2/10 hpf and poor differentiation were associated with decreased DSS. Tumour size ≥50 mm, lymph node involvement, lymphovascular invasion, presence of necrosis and mitotic count ≥2/10 hpf were associated with decreased actuarial RFS. All five staging systems were useful in stratifying the 61 patients according to actuarial DSS. However, the MSKCC grading and ENETS grading systems were not statistically significant in stratifying DSS in the 61 patients. In the 53 patients who underwent curative resection, the WHO, ENETS, MSKCC, AJCC staging and the MSKCC grading systems were successful in stratifying the patients according to actuarial RFS. However, the Bilimoria scoring and ENETS grading systems were not useful in prognosticating these 53 patients. CONCLUSION: All five classification systems were useful for the prognostication of surgically treated PENs in our patient cohort.

Pre-operative stenting is associated with a higher prevalence of post-operative complications following pancreatoduodenectomy.

OBJECTIVES: Whilst there are theoretical benefits from pre-operatively draining the biliary tree prior to pancreatoduodenectomy (PD), the current literature does not support this intervention. The aim of this study was to explore the relationship between pre-operative stenting, bactibilia and outcome in a large United Kingdom tertiary referral practice. METHODS: Patients undergoing PD were identified from a prospectively maintained database. The presence or absence of a stent prior to PD, and the results of bile cultures taken at PD were related to the subsequent post-operative course and the development of complications. RESULTS: 280 patients underwent PD for periampullary malignancies, all of whom presented with jaundice. 118 patients were stented prior to referral (98 ERCP, 20 PTC). Bile cultures were positive more frequently in the stent group (83% vs. 55%; p = 0.000002) and bactibilia was more common after ERCP than PTC (83% vs. 56%; p = 0.006). The overall prevalence of complications was 54% in the stented and 41% in the non-stented group (p = 0.03) with statistical significance achieved for pancreatic leak (p = 0.013) and haemorrhagic complications (p = 0.03). Comparing stent with no stent, there as no difference in the 30-day mortalities (8.5% vs. 6.8%; p = 0.6) or the 1-year mortality rates (35% vs. 28%; p = 0.21). Mortality rates in the infection versus no infection groups were comparable at 30 days (8.5% vs. 5.5%; p = 0.21), and at 1 year (30.7% vs. 26.4%; p = 0.25). CONCLUSIONS: Pre-operative stent insertion prior to PD is associated with increased morbidity but not mortality and this is greatest for stents placed at ERCP.

p38delta/MAPK13 as a diagnostic marker for cholangiocarcinoma and its involvement in cell motility and invasion.

Cholangiocarcinoma (CC) and hepatocellularcarcinoma (HCC) are two main forms of liver malignancies, which exhibit differences in drug response and prognosis. Immunohistotochemical staining for cytokeratin markers has been used to some success in the differential diagnosis of CC from HCC. However, there remains a need for additional markers for increased sensitivity and specificity of diagnosis. In this study, we have identified a p38 MAP kinase, p38delta (also known as MAPK13 or SAPK4) as a protein that is upregulated in CC relative to HCC and to normal biliary tract tissues. We performed microarray gene expression profiling on 17 cases of CC, 12 cases of adjacent normal liver tissue, and three case of normal bile duct tissue. p38delta was upregulated in 16 out of 17 cases of CC relative to normal tissue. We subsequently performed immunohistochemical staining of p38delta in 54 cases of CC and 54 cases of HCC. p38delta staining distinguished CC from HCC with a sensitivity of 92.6% and a specificity of 90.7%. To explore the possible functional significance of p38delta expression in CC, we examined the effects of overexpression and knockdown of p38delta expression in human CC cell lines. Our results indicate that p38delta is important for motility and invasion of CC cells, suggesting that p38delta may play an important role in CC metastasis. In summary, p38delta may serve as a novel diagnostic marker for CC and may also serve as a new target for molecular based therapy of this disease.

Combined hepatocellular and cholangiocarcinoma with sarcomatoid transformation: radiologic-pathologic correlation of a case.

A 71-year-old man presented to our hospital with 3-week history of fever in the background of loss of both weight and appetite over the past 3 months. He was found to have a large 10-cm mass in the right lobe of the liver on a triple-phase computed tomographic scan. The tumor showed a distinct fatty component, with areas of arterial enhancement and venous washout suggestive of hepatocellular carcinoma (HCC), another component showing progressive and late enhancement suggestive of cholangiocarcinoma (CC), and a third component showing persistent hypoenhancement relative to the liver parenchyma. He underwent surgical resection. This was histopathologically a biphasic tumor composed of areas showing hepatocytic differentiation, in contiguity with areas showing infiltrative glands set within fibrous stroma in keeping with combined hepatocellular and cholangiocarcinoma (cHCC-CC). A third component of pleomorphic spindle and epithelioid appearance in keeping with sarcomatous transformation was also found intimately related to the CC component. The patient developed extensive thoracic and abdominal metastases 2 months after surgery and died shortly after.

Accurate preoperative localization of insulinomas avoids the need for blind resection and reoperation: analysis of a single institution experience with 17 surgically treated tumors over 19 years.

INTRODUCTION: Presently, the need for and choice of preoperative localization tests for insulinomas remain controversial. We report the results from a single institution experience whereby the management policy adopted was that of accurate preoperative localization before surgical exploration. MATERIALS AND METHODS: From 1990 to 2008, 17 patients with a clinical and biochemical diagnosis of an insulinoma who underwent surgery were retrospectively reviewed. The diagnosis of all insulinomas were confirmed pathologically. RESULTS: All tumors were localized preoperatively and an average of 2.2 preoperative localization studies including 1.4 noninvasive studies and 0.8 invasive studies were utilized per patient. Invasive localization modalities were more sensitive (92%) than noninvasive modalities in localizing insulinomas (71%). Intra-arterial calcium stimulation with hepatic venous sampling was the most sensitive invasive modality (100%), whereas magnetic resonance imaging was the most sensitive noninvasive modality (63%). Fifteen of 17 tumors (88%) were localized intraoperatively via inspection/palpation and/or intraoperative ultrasonography. Both insulinomas which were not localized intraoperatively were localized correctly to the distal pancreas via preoperative transhepatic portal venous sampling. None of the patients required a blind resection or surgical reexploration for failed localization. All 17 patients underwent complete surgical resection which included eight enucleations and nine distal pancreatectomies with a cure rate of 94% (16/17) at a median follow-up of 35 (range, 1-217) months. The postoperative morbidity and long-term outcome of enucleation was similar to distal pancreatectomy despite a higher rate of microscopic margin involvement. CONCLUSION: Accurate preoperative localization of insulinomas is useful as it eliminates the need for blind distal pancreatectomy and avoids reoperation. Complete surgical resection is the treatment of choice, and whenever possible, a pancreas-sparing approach such as enucleation should be adopted.

Critical appraisal of 232 consecutive distal pancreatectomies with emphasis on risk factors, outcome, and management of the postoperative pancreatic fistula: a 21-year experience at a single institution.

OBJECTIVE: To critically analyze a large single-institution experience with distal pancreatectomy (DP), with particular attention to the risk factors, outcome, and management of the postoperative pancreatic fistula (PF). DESIGN: Retrospective study. SETTING: Tertiary referral center. PATIENTS: A total of 232 consecutive patients with pancreatic or extrapancreatic disease necessitating DP over 21 years. INTERVENTIONS: Twenty-one patients underwent spleen-preserving DP, 117 underwent DP with splenectomy, and 94 underwent DP with multiorgan resection. MAIN OUTCOME MEASURES: The perioperative and postoperative data of patients who underwent DP were analyzed. This included factors associated with postoperative morbidity with particular attention to the PF (defined by the International Study Group of Pancreatic Fistula) and changing trends in operative and perioperative data during the study period. RESULTS: The overall operative morbidity and mortality were 47% (107 patients) and 3% (7 patients), respectively. During the study period, the rates of resection increased from 3 cases to 23 per year, and increasingly these were performed for smaller and incidental lesions. The morbidity rate remained unchanged, but there was a decline in postoperative stay and the need for care in the intensive care unit. Pancreatic fistulas occurred in 72 patients (31%); 41 (18%) were grade A, 13 (6%) grade B, and 18 (8%) grade C. Increased weight, higher American Society of Anesthesiologists score, blood loss greater than 1 L, increased operation time, decreased albumin level, and sutured closure of the stump without main duct ligation were associated with a postoperative PF on univariate analysis. A DP with splenectomy was associated with a higher incidence of grade B or C PF and non-PF-related complications. Ninety-two percent of PFs were successfully managed nonoperatively. Clinical outcomes correlated well with PF grading, as evidenced by the progressive increase in outcome measures such as postoperative stay, readmissions, reoperations, radiologic interventions, and non-PF-related complications from grade A to C PFs. CONCLUSIONS: Pancreatic fistula is the most common complication after DP and its incidence varies depending on the definition applied. Several risk factors for developing a PF were identified. Splenic preservation after DP is safe. The grade of a PF correlates well with clinical outcomes, and most PFs may be managed nonoperatively.

Outcome of distal pancreatectomy for pancreatic adenocarcinoma.

OBJECTIVES: To determine the outcome of patients undergoing distal pancreatectomy for pancreatic adenocarcinoma. METHODS: A retrospective review of 39 patients undergoing distal pancreatectomy for adenocarcinoma. RESULTS: Thirty patients underwent surgery for ductal adenocarcinoma, 5 for malignant intraductal papillary mucinous neoplasm and 4 for mucinous cystadenocarcinoma. Malignant cystic neoplasms were significantly less likely to demonstrate perineural invasion, more likely to be well-differentiated, of lower T stage and of lower AJCC staging compared to ductal adenocarcinoma. These had a longer median disease-specific survival (42 (3-144) vs. 15 (14-16) months, p = 0.002). Eight patients underwent extended resections. These were associated with longer operating times compared to standard resections but there was no difference in surgical morbidity or mortality, blood transfusions, length of hospitalization or long-term survival. Univariate analysis demonstrated that R2 resection, size >30 mm, lymph node involvement, need for perioperative blood transfusion, serum albumin <40 g/l and platelet count <200/microl were predictors of survival for ductal adenocarcinoma. CONCLUSIONS: Malignant cystic neoplasms have less aggressive behavior and more favorable outcome compared to ductal adenocarcinoma. R2 resection, larger tumor size, lymph node involvement, perioperative transfusion, decreased serum albumin and low platelet count are factors associated with decreased survival in patients with ductal adenocarcinoma undergoing distal pancreatectomy.

How useful are clinical, biochemical, and cross-sectional imaging features in predicting potentially malignant or malignant cystic lesions of the pancreas? Results from a single institution experience with 220 surgically treated patients.

BACKGROUND: This study aims to determine the use of preoperative clinical, biochemical, and cross-sectional imaging features for predicting malignancy in cystic lesions of the pancreas (CLP). STUDY DESIGN: Two hundred twenty patients who underwent operations for CLP or suspected CLP were reviewed. Patients were divided into two groups, patients undergoing operations for pseudocysts and patients undergoing operations for suspected cystic neoplasms. The predictive effect of various preoperative factors on the malignant potential of CLP was evaluated. RESULTS: Forty-four patients with a preoperative diagnosis of pseudocysts underwent operations for complications of pseudocyst. Forty-two were confirmed pathologically to have pseudocysts, but two were found, unexpectedly, to harbor malignant lesions. One hundred seventy-six patients underwent operations for suspected pancreatic cystic neoplasms. There were 70 benign, 51 potentially malignant, and 55 malignant CLP. On multivariate analysis, three factors, ie, elevated serum carcinoembryonic antigen (CEA) or carbohydrate antigen 19-9; cyst size > 3 cm; and presence of one or more of three morphologic features, such as solid component; peripheral calcification; and main duct dilation on cross-sectional imaging were independent predictors of malignancy. Presence of two or three of these factors had a positive predictive value of 88% in predicting a premalignant or malignant CLP. CONCLUSIONS: Most pancreatic pseudocysts can be accurately diagnosed preoperatively. In patients with suspected pancreatic cystic neoplasms, elevated serum CEA or carbohydrate antigen 19-9, cyst size > 3 cm, and presence of suspicious morphologic features on imaging are predictors of potentially malignant or malignant CLP. Patients with a high likelihood of a potentially malignant or malignant lesion based on these three factors should undergo operation without additional investigations.

Pancreatic cysts: a proposed management algorithm based on current evidence.

BACKGROUND: Currently, the management strategy of pancreatic cyst (PC) remains controversial because of the inability to diagnose this type of cyst accurately and the limited knowledge of its natural history. Previously, many clinicians have advocated an aggressive resectional policy. This approach is no longer appropriate, and the number of PCs detected incidentally has increased. This study reviews the present literature and attempts to provide a management algorithm of pancreatic cysts based on currently available evidence. METHODS: A Medline search was conducted to identify studies investigating PC, with particular emphasis placed on studies addressing its diagnosis and management. Additional articles were obtained from the reference lists of key articles and recent reviews. COMMENTS: Based on current evidence, the optimal management of PC remains an art and should be individualized based on the risk-benefit ratio of surgery, which is influenced by multiple factors, such as the patient's potential life expectancy, surgical risk; and malignant potential of the cyst. Our proposed management algorithm is based on an individual's predicted risk-benefit ratio of surgery. Prospective evaluation of the algorithm is needed to determine its integrity.

Solid pseudopapillary neoplasms of the pancreas: an updated experience.

INTRODUCTION: The aim of this study is to report an update of the surgical experience at a single institution with these unusual tumors. METHODS: Sixteen consecutive patients who underwent surgery for a pathologically confirmed solid pseudopapillary neoplasm (SPPN) were retrospectively reviewed. RESULTS: Fifteen of the patients were female and the median age at diagnosis was 30 years (range, 14-53 years). Abdominal and back pain were the most common presenting symptoms. The tumors appeared on cross-sectional imaging as solid and cystic (n = 14) or cystic (n = 2) masses. The median tumor size was 9.5 cm (range, 5.0-24.0 cm). All 16 patients had curative resections including 3 pancreaticoduodenectomies and 13 distal pancreatectomies. Three patients required extended resections including pancreaticoduodenectomy with portal vein resection, distal pancreatectomy with tranverse colectomy, and distal pancreactomy with omentectomy. Two of the resections were R1 whereas 14 were R0. All patients were alive and disease-free at a median follow-up of 43 months (range, 3-186 months). CONCLUSION: SPPNs should be considered in young women presenting with a large solid-cystic pancreatic mass. Aggressive en bloc resection should always be attempted including resection of concomitant metastases as patients demonstrate excellent long-term survival even in the presence of distant spread.

A review of mucinous cystic neoplasms of the pancreas defined by ovarian-type stroma: clinicopathological features of 344 patients.

INTRODUCTION: Despite formal definitions of mucinous cystic neoplasms (MCNs) and intraductal papillary neoplasms (IPMNs) by the World Health Organization (WHO) and Armed Forces Institute of Pathology (AFIP), several controversies with regard to MCNs remain. The aim of this review was to determine the clinicopathological features of MCNs defined by ovarian-type stroma (OS) as proposed by the WHO and AFIP and to compare them with MCNs defined by less stringent criteria. METHODS: A MEDLINE search was conducted to identify English-language articles on pancreatic MCNs from 1996 to 2005. Twenty-five studies were identified. The studies were divided into 2 groups: group A included 10 studies with 344 patients whereby the presence of OS was a criteria for the diagnosis of MCNs, and group B, included 15 studies comprising 761 patients whereby the presence of OS was not mandatory for the diagnosis of MCNs. RESULTS: Patients in group A (MCNs as defined by OS) were almost always female (99.7%), with a mean age of 47 (range, 18-95) years. MCNs were located predominantly in the body or tail of the pancreas (94.6%) and had a mean size of 8.7 cm (range, 0.6-35 cm); 76% were symptomatic, 6.8% demonstrated ductal communication, and 27% were malignant. At a mean follow-up of 57.5 (range, 1-264) months and 43 (range, 2-257) months after surgery, 97.9% of benign and 61.9% of malignant neoplasms were disease free, respectively. Patients in group B were older and had a higher proportion of males. Neoplasms were more evenly distributed in the pancreas, were smaller, communicated more frequently with the pancreatic duct, and were composed of a higher proportion of malignant tumors compared with group A. Their clinicopathological features were intermediate between those of group A and patients with IPMN. CONCLUSION: Pancreatic MCNs with OS have unique and distinct clinicopathological features. MCNs should be defined by the presence of OS, as it is the most reliable way of distinguishing MCNs from IPMN. Adoption of "looser" criteria will result in misclassification of some IPMNs as MCNs.

Clinicopathological features of patients with concomitant intraductal papillary mucinous neoplasm of the pancreas and pancreatic endocrine neoplasm.

BACKGROUND/AIMS: The occurrence of concomitant pancreatic endocrine neoplasm (PEN) and intraductal papillary neoplasm (IPMN) of the pancreas has rarely been reported. We describe our experience with 3 patients with this association and review the existing literature. METHODS: From 1990 to 2005, 65 patients who underwent surgery for a PEN or IPMN were retrospectively reviewed. Forty-three patients had a PEN, 19 had an IPMN and 3 had both an IPMN and PEN. The 3 patients with concomitant IPMN and PEN are the focus of the current study and their clinicopathological features are reported together with 7 patients previously reported in the literature. RESULTS: There were 10 patients with a median age of 62 years (range 40-73). The male:female ratio was equal. Seven of 10 patients were symptomatic and the most common symptoms were abdominal pain (n = 5), jaundice (n = 2) and loss of weight (n = 2). The median size of the endocrine neoplasms was 14 mm (range 2-30) and they occurred in the head (n = 3), body (n = 2) and tail (n = 5). Seven of the PENs were classified as benign, 2 were potentially malignant, and 1 was frankly malignant with lymph node involvement. None of the endocrine neoplasms were functioning. The IPMNs were found in the tail (n = 4), head (n = 3), head and body (n = 1), body (n = 1) and the entire pancreas (n = 1). Five of these neoplasms were benign, 2 were borderline and 3 were malignant (1 carcinoma in situ). CONCLUSION: The occurrence of concomitant IPMN and PEN is more frequent than would be expected. However, it is difficult in the present analysis to determine if this association is more than just fortuitous.