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C Pasquali

Publications and source records attributed to C Pasquali.

At least 37 records · Page 2Linked to original sources
PubMed1998

Neisseria gonorrhoeae porin modulates phagosome maturation.

The porin (PorB) of Neisseria gonorrhoeae has been implicated in the pathogenesis of this species. Porin is believed to translocate from the bacterial outer membrane into target cell membranes affecting various cell functions. Here we investigated the effect of porin on phagosome maturation. Phagocytosis of latex beads by human macrophages was allowed in the presence or absence of purified porin. Isolation of latex bead-containing phagosomes and subsequent two-dimensional gel electrophoresis revealed substantial differences in the phagosomal protein composition. Immunoblotting detected higher amounts of annexin II and the early endocytic markers Rab5 and transferrin receptor and decreased levels of the late endocytic markers Rab7 and cathepsin D in phagosomes obtained in the presence of porin compared with those obtained in its absence. Furthermore, association of Rab4 with the latex bead-containing phagosomes was revealed by flow cytometry. The amount of this small GTPase was markedly higher in the phagosomes isolated in the presence of porin. The data thus indicate that neisserial porin is itself able to arrest phagosome maturation within macrophages.

Bacterial Outer Membrane Proteins↗
PubMed1998

Neuroendocrine tumor imaging: can 18F-fluorodeoxyglucose positron emission tomography detect tumors with poor prognosis and aggressive behavior?

We evaluated the clinical value of positron emission tomography (PET) using 18F-fluorodeoxyglucose (FDG) for neuroendocrine tumor (NET) detection. Sixteen patients with cytologically or histologically proved NETs were investigated. Patients were divided in two groups of eight patients each according to the clinicopathologic features related to prognosis: slow-growing NETs and aggressive NETs. Results of FDG tumor uptake as detected by PET were compared with computed tomography (CT) scans and with scans obtained with 111In-octreotide scintigraphy (n = 13). Tumor FDG uptake was increased in the primary lesion of all eight aggressive NETs; the tracer was shown also in lymph nodes, liver metastases, or both in five of six of them (83%). In four cases, additional unknown tumor sites undetected by CT scan were identified. A slight positivity was found in only one of eight cases with a slow-growing NET. The overall octreotide scintiscan sensitivity was 85%, but in the aggressive NETs it failed to detect the primary lesion in two of seven cases. Uptake of the tracer in some but not all tumor lesions in the same patient was seen by both FDG-PET and octreotide scintiscans. From our limited experience 18F-FDG PET seems to be useful for identifying NETs characterized by rapid growth or aggressive behavior. Uptake of the FDG tracer by the tumor may be related to a worse prognosis. Despite the heterogeneity of tracer uptake in the various lesions of NETs with multiple tumor sites, FDG-PET was able to detect unsuspected distant metastases, contributing to better staging of advanced disease.

Adult↗
PubMed1998

Portal but not peripheral serum levels of interleukin 6 could interfere with glucose metabolism in patients with pancreatic cancer.

UNLABELLED: Interleukin 6 (IL-6), an autocrine growth factor for many tumors, seems to favour tumor spread to the liver. Our aims were first to evaluate the pattern of portal and systemic IL-6 levels in patients with pancreatic cancer (PC, n = 18) and chronic pancreatitis (CP, n = 22) compared with controls (CS, n = 20); and second, to ascertain whether there was any relation between IL-6 levels and tumor spread or PC-associated Diabetes mellitus. For all subjects, a fasting serum sample was obtained from a cubital vein; a portal serum sample was obtained from nine PC and three CP patients. In cubital and portal sera we measured IL-6, interleukin 1 beta (IL-1b), CA 19-9, c-reactive protein (CRP) and amylase. Systemic IL-6 levels were significantly higher in PC patients than in CS. In PC, portal IL-6 levels were significantly higher than the corresponding systemic values. The same pattern was found in the three CP patients, whereas IL-1b, CA 19-9, CRP and amylase portal levels were the same as systemic values. No correlation was found between PC stage and systemic or portal IL-6 levels. Portal IL-6 levels were correlated with the corresponding fasting serum glucose values. A significant correlation was found between IL-6 values and CRP, ALT, total bilirubin, GGT and creatinine, but not amylase. IN CONCLUSION: (1) Portal IL-6, which is partly of pancreatic origin, is first metabolised in the liver; (2) Systemic IL-6 reflects hepatic and renal functions rather than local conditions in the pancreas; (3) IL-6 does not appear to influence PC spread; (4) IL-6, which is released in large amounts by the inflamed pancreas, may contribute to determining diabetes, thus interfering with the signal transducing pathways involved in glucose metabolism in liver cells.

Aged↗
PubMed1998

Standard versus extended lymphadenectomy associated with pancreatoduodenectomy in the surgical treatment of adenocarcinoma of the head of the pancreas: a multicenter, prospective, randomized study. Lymphadenectomy Study Group.

OBJECTIVE: The study was conducted to determine whether the performance of an extended lymphadenectomy and retroperitoneal soft-tissue clearance in association with a pancreatoduodenal resection improves the long-term survival of patients with a potentially curable adenocarcinoma of the head of the pancreas. SUMMARY BACKGROUND DATA: The usefulness of performing an extended lymphadenectomy and retroperitoneal soft-tissue clearance in conjunction with a pancreatoduodenal resection in the treatment of ductal adenocarcinoma of the head of the pancreas is still unknown. Published studies suggest a benefit for the procedure in terms of better long-term survival rates; however, these studies were retrospective or did not prospectively evaluate large series of patients. MATERIALS AND METHODS: Eighty-one patients undergoing a pancreatoduodenal resection for a potentially curable ductal adenocarcinoma of the head of the pancreas were randomized to a standard (n = 40) or extended (n = 41) lymphadenectomy and retroperitoneal soft-tissue clearance in a prospective, multicentric study. The standard lymphadenectomy included removal of the anterior and posterior pancreatoduodenal, pyloric, and biliary duct, superior and inferior pancreatic head, and body lymph node stations. In addition to the above, the extended lymphadenectomy included removal of lymph nodes from the hepatic hilum and along the aorta from the diaphragmatic hiatus to the inferior mesenteric artery and laterally to both renal hila, with circumferential clearance of the origin of the celiac trunk and superior mesenteric artery. Patients did not receive any postoperative adjuvant therapy. RESULTS: Demographic (age, gender) and histopathologic (tumor size, stage, differentiation, oncologic clearance) characteristics were similar in the two patient groups. Performance of the extended lymphadenectomy added time to the procedure, although the difference did not reach statistical significance (397 +/- 50 minutes vs. 372 +/- 50 minutes, p > 0.05). Transfusion requirements, postoperative morbidity and mortality rates, and overall survival did not differ between the two groups. When subgroups of patients were analyzed, using an a posteriori analysis that was not planned at the time of study design, there was a significantly (p < 0.05) longer survival rate in node positive patients after an extended rather than a standard lymphadenectomy. The survival curve of node positive patients after an extended lymphadenectomy could be superimposed onto the curves of node negative patients. Survival curves in node negative patients did not differ according to the magnitude of the lymphadenectomy. Multivariate analysis of all patients showed that long-term survival was affected by tumor differentiation (well vs. moderately vs. poorly differentiated, p > 0.001), diameter (< or = 2.0 cm. vs. > 2.0 cm., p < 0.01), lymph node metastasis (absent vs. present, p < 0.01) and need for 4 or more units of transfused blood (< 4 vs. > or = 4, p <0.01). CONCLUSIONS: The addition of an extended lymphadenectomy and retroperitoneal soft-tissue clearance to a pancreatoduodenal resection does not significantly increase morbidity and mortality rates. Although the overall survival rate does not differ in the two groups, there appears to be a trend toward longer survival in node positive patients treated with an extended rather than a standard lymphadenectomy.

Adenocarcinoma↗
PubMed1998

Transforming growth factor beta, fibrogenesis and hyperglycemia in patients with chronic pancreatitis.

UNLABELLED: It has been suggested that transforming growth factor beta (TGFb) mediates liver fibrosis, which can be monitored by the serum determination of the N-terminal peptide of type III procollagen (PIIIP) and laminin. Fibrosis is also an important phenomenon in patients with chronic pancreatitis (CP). In 23 patients with CP, 38 with liver cirrhosis (LC) and 20 healthy controls we compared the serum patterns of PIIIP, laminin and TGFb and assessed whether in CP these markers are correlated with exocrine and endocrine function. In patients with LC, PIIIP and laminin levels were significantly higher, whereas TGFb levels were significantly lower than those of controls. In CP patients, no significant variations were found for PIIIP and laminin, although levels were high in 7/23 and in 5/23 patients, respectively. TGFb levels in CP patients were higher than those in LC patients, levels being raised in 6/23 patients. In LC patients an inverse correlation was found between PIIIP and TGFb, whereas in CP patients, a direct correlation was found between TGFb and PIIIP. Moreover, in CP patients, there was also a positive correlation between TGFb and fasting serum glucose levels, while laminin was correlated with PABA test results. IN CONCLUSION: serum biochemical markers of liver fibrosis can be considered of limited value in assessing pancreatic fibrosis; in liver cirrhosis there may be a negative feed-back regulation between TGFb production and the fibrogenetic process; and in chronic pancreatitis TGFb appears to favor fibrosis on the one hand and the development of hyperglycemia on the other.

Adult↗
PubMed1997

Two-dimensional gel electrophoresis analysis of endovacuolar organelles.

Cells perform their multiple functions with the aid of a series of distinct membrane organelles. In the last years, many of these compartments have been isolated, purified, and extensively studied. The major roles of each organelle in the cell are well understood. However, most of the molecular basis by which they perform their functions is poorly known. The recent identification and study of a handful of proteins associated with endovacuolar compartments has had a major impact on the understanding of the molecular details of organelle functions even though two-dimensional (2-D) gel analysis indicates that hundreds of proteins are typically associated with a complex organelle. This shows that many details and surprises are still to come for cell biologists. In the present study, we have analyzed and compared different organelles of the endocytic and phagocytic apparatus using 2-D gel electrophoresis.

Animals↗
PubMed1997

Preparative two-dimensional gel electrophoresis of membrane proteins.

Electrophoretic techniques, and especially two-dimensional gel electrophoresis (2-DE), have provided an indispensable set of tools for the separation of complex protein mixtures as well as for the identification of protein-protein interactions. Nevertheless, after its introduction more than twenty years ago and even with recent technical developments, the separation of integral and peripheral membrane proteins, in amounts sufficient for microsequencing, is still a difficult task. Lipids present in the membrane as well as the low solubility of hydrophobic membrane proteins result in protein aggregation both on the sample application point and on isoelectric focusing. As a consequence many proteins do not enter the first or second dimension of 2-DE. Here we describe the modification of a protocol using a combination of 3-[(3-cholamidopropyl)-dimethylammonio]-1-propane sulfonate (CHAPS), chaotropic agents (thiourea, urea), Tris base and reducing agents (1,4-dithioerythritol) to improve solubilization of integral and peripheral membrane proteins. Preparative amounts of membrane proteins (up to 2 mg) were loaded during reswelling of dry immobilized pH gradients and the resulting Coomassie staining patterns were largely superimposable with silver-stained gels obtained from identical samples (4 microg). This indicates that the recovery of proteins from the sample is not significantly compromised by the scale-up procedure. A direct application of this method for the characterization and identification of membrane proteins from cellular organelles is described in another paper in this issue (I. Fialka et al., Electrophoresis 1997, 18, 2582-2590).

Animals↗
PubMed1997

Subcellular fractionation of polarized epithelial cells and identification of organelle-specific proteins by two-dimensional gel electrophoresis.

Protein targeting and sorting is accomplished by complex vesicular transport processes that are tightly regulated within a cell. This is especially important for epithelial cells because correct delivery of newly synthesized proteins as well as recycling and sorting of internalized membrane proteins is essential for the establishment and preservation of cellular polarity. Many transport events, linking various subcellular compartments, have been analyzed, but many transport mechanisms still remain unresolved. In this study we attempted to identify proteins specifically associated with distinct organelles in murine mammary epithelial cells (EpH4). We isolated subcellular compartments by continuous sucrose gradient centrifugation in order to further analyze their protein composition by high-resolution two-dimensional gel electrophoresis (2-DE). The successful separation of late endosomes (LE), early endosomes (EE) and most of the rough endoplasmic reticulum (RER) was confirmed by subsequent analysis of gradient fractions for compartment-specific enzymes and marker proteins. Both Golgi and plasma membrane (PM) were found to partially co-purify with EE in such gradients. Characteristic polypeptide patterns were revealed on 2-DE gels for fractions enriched in membranes of different origin. Based on improved sample preparation and loading techniques (this issue, C. Pasquali et al., Electrophoresis, 1997, 18, 2573-2581), we were able to identify several proteins by immunoblotting or microsequencing of Coomassie-stained spots. This will be the basis for a further characterization of organelle-specific molecules in epithelial cells as well as for the establishment of a 2-DE reference map of membrane proteins from murine mammary epithelium.

Animals↗
PubMed1997

Melanie II--a third-generation software package for analysis of two-dimensional electrophoresis images: I. Features and user interface.

Although two-dimensional electrophoresis (2-DE) computer analysis software packages have existed ever since 2-DE technology was developed, it is only now that the hardware and software technology allows large-scale studies to be performed on low-cost personal computers or workstations, and that setting up a 2-DE computer analysis system in a small laboratory is no longer considered a luxury. After a first attempt in the seventies and early eighties to develop 2-DE analysis software systems on hardware that had poor or even no graphical capabilities, followed in the late eighties by a wave of innovative software developments that were possible thanks to new graphical interface standards such as XWindows, a third generation of 2-DE analysis software packages has now come to maturity. It can be run on a variety of low-cost, general-purpose personal computers, thus making the purchase of a 2-DE analysis system easily attainable for even the smallest laboratory that is involved in proteome research. Melanie II 2-D PAGE, developed at the University Hospital of Geneva, is such a third-generation software system for 2-DE analysis. Based on unique image processing algorithms, this user-friendly object-oriented software package runs on multiple platforms, including Unix, MS-Windows 95 and NT, and Power Macintosh. It provides efficient spot detection and quantitation, state-of-the-art image comparison, statistical data analysis facilities, and is Internet-ready. Linked to proteome databases such as those available on the World Wide Web, it represents a valuable tool for the "Virtual Lab" of the post-genome area.

Algorithms↗
PubMed1997

Recurrence after resection for ductal adenocarcinoma of the pancreas.

We analyzed the pattern of failure and clinicopathologic factors influencing the disease-free survival of 78 patients who died after macroscopic curative resection for pancreatic cancer. Local recurrence was a component of failure in 56 patients (71.8%) and hepatic recurrence in 48 (61.5%), both accounting for 97% of the total recurrence rate. About 95% of recurrences occurred by 24 months after operation. Median disease-free survival time was 8 months, and cumulative 1-, 3-, and 5-year actuarial disease-free survival rates were 66%, 7%, and 3%, respectively. Multivariate analysis showed that tumor grade (p = 0.04), microscopic radicality of resection (p = 0.04), lymph node status (p = 0.01), and size of the tumor (p = 0.005) were independent predictors of disease-free survival. Patterns of failure and disease-free survival were not statistically influenced by the type of surgical procedure performed. Median survival time from the detection of recurrence until death was 7 months for local recurrence versus 3 months for hepatic or local plus hepatic recurrence (p < 0.05). From our experience and the data collected from the literature, it appears that surgery alone is an inadequate treatment for cure in patients with pancreatic carcinoma. Effective adjuvant therapies are needed to improve locoregional control of pancreatic cancer after surgical resection.

Aged↗
PubMed1997

Ductal adenocarcinoma of the body and tail of the pancreas.

BACKGROUND: Carcinoma arising from the body and tail of the pancreas is less frequent than pancreatic head cancer, and its prognosis is known to be worse. This aggressive behavior is reported by few large clinical studies. STUDY DESIGN: We retrospectively reviewed our 24 years experience on adenocarcinoma of the body and tail of the pancreas and analyzed survival and longterm results after resection. Recent large series on cancer of the distal pancreas were also reviewed. RESULTS: Among 148 patients observed, 109 were surgically treated. Resectability rate was 16%; ductal adenocarcinoma in 22% of patients who underwent surgery was resectable. Macroscopic radical resection was achieved in only 16 cases. Overall 5-year survival rate was 2%. In resected cancers the actual 5-year survival rate was 12.5%. Patients with unresectable cancers did not survive more than 17 months. All three patients who survived more than 5 years had a small tumor (T1 according to TNM staging). In the literature, among 360 evaluable resected patients, only 7 survived at 5 years (2%). CONCLUSIONS: The prognosis for patients with adenocarcinoma of the distal pancreas is poor, even after resection of the tumor; however, the results are not substantially different for those reported after resection for pancreatic head carcinoma. Surgical resection can offer longterm survival for patients with localized cancer.

Carcinoma, Ductal, Breast↗
PubMed1997

Expression of mucin-like carcinoma-associated antigen in the cyst fluid differentiates mucinous from nonmucinous pancreatic cysts.

OBJECTIVES: Differential diagnosis of pancreatic cystic lesions may be difficult: the main problem is to distinguish mucinous neoplasms from nonmucinous cysts. We evaluated the usefulness of the mucin-like carcinoma-associated antigen (MCA) in the fluid of pancreatic cysts for detecting mucinous neoplasms. Results were compared with those of CA 15-3, carcinoembryonic antigen (CEA), and CA 72-4 fluid content, and cytology. METHODS: Twenty-four pancreatic cyst fluids were collected from 10 pseudocysts, eight mucinous cystic tumors, and six serous cystadenomas. RESULTS: MCA was elevated in seven of eight mucinous tumors (sensitivity 87.5%, specificity 100%). A significant difference was found between MCA levels in mucinous neoplasms versus pseudocysts (p = 0.0003) and serous cystadenomas (p = 0.001). Mean MCA levels were higher (133.7 U/ml) in mucinous cystadenocarcinomas than in cystadenomas (37.5 U/ml). The sensitivity of CA 15-3, CEA, and CA 72-4 in detecting mucinous neoplasms was 50, 87.5, and 87.5%, respectively, with a specificity of 94%, 44%, and 94%, respectively. Cytology showed mucinous epithelial cells in only four of eight mucinous neoplasms, with a specificity of 100%. CONCLUSIONS: These data suggest that MCA determination in the cyst fluid is a promising new tumor marker for the preoperative diagnosis of mucinous cystic neoplasms of the pancreas.

Antigens, Neoplasm↗
PubMed1996

Serum tumor markers and cyst fluid analysis are useful for the diagnosis of pancreatic cystic tumors.

BACKGROUND: This study was performed to evaluate the utility of serum and cyst fluid analysis for enzymes (amylase and lipase) and tumor markers (carcinoembryonic antigen, CA 19-9, CA 125, and CA 72-4) in the differential diagnosis of cystic pancreatic lesions. METHODS: Serum and cyst fluid were obtained from 48 patients with pancreatic cysts (21 pseudocysts, 14 mucinous cystic neoplasms, 6 ductal carcinomas, and 7 serous cystadenomas), observed between 1989 and 1994. RESULTS: Serum CA 19-9 levels were significantly higher in ductal carcinomas (all > 100 U/mL) and mucinous cystic neoplasms (P < 0.05). CA 72-4 cyst fluid levels were significantly higher in mucinous cystic tumors (P < 0.005), with 95% specificity and 80% sensitivity in detecting mucinous or malignant cysts. A combined assay of serum CA 19-9 and cyst fluid CA 72-4 correctly identified 19 of 20 (pre-) malignant lesions (95%), with only 1 false-positive result (3.6%). Cytology showed a sensitivity of 48% and specificity of 100%. CONCLUSIONS: Any pancreatic cyst with high serum CA 19-9 values, positive cytology, or high CA 72-4 in the fluid should be considered for resection.

Adenocarcinoma↗
PubMed1996

Large-scale amino-acid analysis for proteome studies.

Amino-acid analysis is a relatively new method for identification of proteins separated by two-dimensional gel electrophoresis and blotted onto polyvinylidene difluoride (PVDF) membranes. This article describes modified amino-acid analysis methods for this purpose. Streamlined sample handling is a key feature of the process. To minimise sample manipulation, a single vial is used for hydrolysis and the protein hydrolysate on PVDF membrane is extracted by a one-step procedure. The hydrolysate should not be stored for long periods before analysis. Applications of the technique are presented to demonstrate the identification procedure. This approach is the most cost-effective and time-effective first step in mass protein screening for a large-scale proteome project.

Amino Acids↗
PubMed1996

Nuclear DNA content and pathology in radically treated pancreatic carcinoma. The prognostic significance of DNA ploidy, histology and nuclear grade.

BACKGROUND: Nuclear DNA content and pathology are considered to be prognostically relevant in several solid tumors, but controversial findings have emerged in pancreatic carcinoma (PC). Histopathology and DNA ploidy were each correlated with survival in radically treated PC to ascertain the hierarchy of their prognostic significance. METHODS: DNA ploidy was assessed by flow cytometry (FC) in neoplastic tissue samples from 60 patients with PC who were followed until death. Representative neoplastic areas were obtained by microdissection from archival paraffin embedded material (excluding any carcinoma with a coefficient of variation of the G0/G1 peak higher than 8%). Histologic data and FC patterns were related to prognostic behavior using univariate multivariate statistical analysis. RESULTS: Aneuploid cancers were detected in 39 of 60 patients. Univariate analysis showed that histologic grade, nuclear grade, and ploidy were significantly related to prognosis. On multivariate analysis, only histologic grade and DNA ploidy (diploid vs. aneuploid) were significant with significant interaction. CONCLUSIONS: The prognostic value of pathology and ploidy was demonstrated in patients treated radically for PC. As in other tumors characterized by a short survival, the clinical usefulness of any prognostic parameters is somewhat limited. However, the significant relationship between prognosis and DNA ploidy might be of interest in a cost-benefit analysis for selecting patients in whom an attempt at radical surgical treatment or adjunctive chemotherapy may be justified.

Adult↗
PubMed1996

Survival after resection for ductal adenocarcinoma of the pancreas.

A retrospective study was performed of 113 patients who underwent surgical resection of carcinoma of the pancreas from 1970 to 1992. The postoperative mortality rate was 15 per cent (5 per cent in the last 11 years). The actuarial 5-year survival rate was 12 per cent. Survival was significantly influenced by age (P = 0.03), vascular resection (P = 0.02), radicality of operation (P = 0.01), number of transfused blood units (P = 0.01), tumour differentiation (P = 0.002), lymph node status (P = 0.001), perineural invasion (P = 0.01), tumour size (P = 0.008), preoperative diabetes (P = 0.001) and stage (P = 0.0001). Multivariate analysis showed that stage, diabetes, age and grade were independent predictors of long-term survival. The type of pancreatic resection (Whipple, subtotal, total or distal pancreatectomy) did not influence prognosis. The 5-year survival rate was 14 per cent in the period 1970-1981 and 11 per cent in the period 1982-1992, with no statistical difference. These results suggest that patient characteristics and tumour findings rather than operative procedures affect long-term survival after resection for pancreatic carcinoma.

Adult↗
PubMed1996

Federated two-dimensional electrophoresis database: a simple means of publishing two-dimensional electrophoresis data.

While a two-dimensional electrophoresis (2-DE) database is a relatively old concept, in recent years it generated renewed interest within the 2-DE community due to two main factors: (i) The high reproducibility of the current 2-DE method allows 2-DE images to be exchanged and compared between laboratories. (ii) The recent development of faster and more powerful techniques for protein identification such as microsequencing, matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) and amino acid composition makes the production of reference protein maps and 2-DE databases cost- and time-effective. Additionally, the Internet network's current increase in popularity, combined with the rapid growth of Internet-connected laboratories, provides a straightforward means of publishing and sharing 2-DE data. While a small number of laboratories have already successfully published their data over the net, the increasing number of 2-DE database servers that are currently being set up will sooner or later require some kind of standardization. Unfortunately, standardization can be a long and cumbersome process inevitably leading to undesirable compromises. A federated database offers a simple and efficient way to publish and share 2-DE data without the need for standardization. Taking advantage of Internet protocols such as World Wide Web, they allow each laboratory to maintain their own database and to interconnect it with other similar databases through the use of active cross-references. This paper first presents guidelines for building a federated 2-DE database that may easily be followed by most laboratories. It then briefly reviews the state-of-the-art in networked 2-DE databases, and finally describes the SWISS-2DPAGE database which fully implements the concept of a federated 2-DE database.

Computer Communication Networks↗