Antonio Bonora

Behavior of antibiotics during human necrotizing pancreatitis.

The aim of the study was to verify whether antibiotics excreted by the normal pancreas are also excreted in human necrotizing pancreatitis, reaching the tissue sites of the infection. Twelve patients suffering from acute necrotizing pancreatitis were treated with imipenem-cilastatin (0.5 g), mezlocillin (2 g), gentamicin (0.08 g), amikacin (0.5 g), pefloxacin (0.4 g), and metronidazole (0.5 g). Serum and necrotic samples were collected simultaneously at different time intervals after parenteral drug administration by computed tomography-guided needle aspiration, intraoperatively, and from surgical drainages placed during surgery. Drug concentrations were determined by microbiological and high-performance liquid chromatography assays. All antibiotics reached the necrotic tissues, but with varying degrees of penetration, this being low for aminoglycosides (13%) and high in the case of pefloxacin (89%) and metronidazole (99%). The concentrations of pefloxacin (13.0 to 23 micrograms/g) and metronidazole (8.4 micrograms/g) in the necrotic samples were distinctly higher than the MICs for the organisms most commonly isolated in this disease; the concentrations in tissue of imipenem (3.35 micrograms/g) and mezlocillin (8.0 and 15.0 micrograms/g) did not always exceed the MICs for 90% of strains tested, whereas the aminoglycoside concentrations in necrotic tissue (0.5 microgram/g) were inadequate. Repeated administration of drugs (for 3, 7, 17, and 20 days) seems to enhance penetration of pefloxacin, imipenem, and metronidazole into necrotic pancreatic tissue. The choice of antibiotics in preventing infected necrosis during necrotizing pancreatitis should be based on their antimicrobial activity, penetration rate, persistence, and therapeutic concentrations in the necrotic pancreatic area. These requisites are provided by pefloxacin and metronidazole and to a variable extent by imipenem and mezlocillin.

SEL1L expression in pancreatic adenocarcinoma parallels SMAD4 expression and delays tumor growth in vitro and in vivo.

Recent data suggest that SEL1L may play an important role in pancreatic carcinoma, similar to breast cancer, where the expression of SEL1L has been associated with a reduction in both proliferative activity in vitro and clinical tumor aggressiveness. To investigate this possibility, we examined the expression of Sel1L in a series of primary pancreatic carcinomas by immunohistochemistry and characterized the effects of Sel1L overexpression both in vitro and in vivo. In 74 pancreatic cancers analysed, 36% lacked Sel1L expression, although there was no significant correlation between the expression of Sel1L and any clinicopathologic parameter, including survival. However, immunohistochemical reactivity for Sel1L and Dpc4/Smad4 was concordant in 69% of cases (χ2 test P<0.004). Overexpression of SEL1L in stably transfected pancreatic cancer cells caused both a decrease in clonogenicity and anchorage-independent growth as well as a significant increase in the levels of activin A and SMAD4. When implanted in nude mice, Suit-2-SEL1L-overexpressing clones displayed a considerably reduced rate of tumor growth. Thus, it can be hypothesized that Sel1L plays an important function in the growth and aggressiveness of pancreatic carcinoma. Moreover, our data provide evidence that SEL1L has an impact on the expression of genes involved in regulation of cellular growth, possibly through the TGF-β signaling pathway.

Role of chemoembolization in synchronous liver metastases from pancreatic endocrine tumours.

Endocrine tumours of the pancreas, even in case of liver involvement, are generally characterized by a slower evolution and a better prognosis, if compared with ductal carcinoma. This fact gives reason to a radical surgical approach, whenever possible, and to the research of any effective adjuvant treatment. For this purpose, hepatic transarterial chemoembolization (TACE) has been proposed in recent years for the treatment of metastatic endocrine tumours. Out of 80 patients suffering from endocrine tumours of the pancreas, observed between January 1985 and December 1996, 28 (35%) presented liver metastases at the time of diagnosis. Twelve of these patients were submitted to palliative resection of pancreatic tumour and one or more cycles of TACE. Overall survival was 50% (6/12); median survival was 35.4 months (range 4–75). These results suggest that chemoembolization, combined with surgical resection of primary malignancy, appears to be able to control the disease for a certain time and to increase the survival rate.

Successful xenografting of cryopreserved primary pancreatic cancers.

Abstract. In order to assess the suitability of cryopreserved neoplastic tissues for xenografting into nude (nu/nu) mice, we compared the take rate in 28 samples of pancreatic ductal carcinoma. Eleven fresh samples were implanted in nu/nu mice, and 17 were frozen in cryopreserving solution and implanted at a later time. All samples were examined for the presence of neoplastic tissue in cryostat sections. A total of 15 tumors grew in the animals; five from the freshly implanted samples and ten from those cryopreserved. Ten xenografted tumors were characterized for alterations in p53, K-ras, and p16 genes, which were found in six, eight, and nine cases, respectively. Our results demonstrate that the take rate for xenografting is comparable between cryopreserved and fresh tissue samples. The procedure allows for the exchange of tumor material between institutions and permits the establishment of centralized facilities for the storage of an array of different primary tumor samples suitable for the production of in vivo models of cancers.

Pancreatic cystic manifestations in von Hippel-Lindau disease

SummaryConclusionIn view of the frequent absence of symptoms related to pancreatic lesions, screening tests for VHL should always include assessment of the pancreas and, considering the frequency of polycystic manifestations, VHL should always be borne in mind in the differential diagnosis of multiple pancreatic cysts, especially when occurring in young patients and in the absence of a positive history of pancreatic disease.BackgroundVon Hippel-Lindau disease (VHL) is a hereditary disease transmitted with an autosomal dominant character and characterized by hemangioblastomas of the central nervous system and retina, renal tumors and cysts, and pheochromocytoma. Pancreatic manifestations of VHL are reported in the literature with incidences ranging from 16 to 29% of cases and consist mainly in cystadenomas of the serous type and in multiple cystic lesions, often with complete replacement of the gland.Methods and ResultsWe report five cases of VHL with a polycystic pancreas as the main or only manifestation, all devoid of symptoms related to involvement of the pancreas, who were referred to our Pancreatic Surgery center with diagnoses of multiple pancreatic pseudocysts of undefined origin.

Elevated urinary levels of urokinase-type plasminogen activator receptor (uPAR) in pancreatic ductal adenocarcinoma identify a clinically high-risk group

BackgroundThe urokinase plasminogen activator receptor is highly expressed and its gene is amplified in about 50% of pancreatic ductal adenocarcinomas; this last feature is associated with worse prognosis. It is unknown whether the level of its soluble form (suPAR) in urine may be a diagnostic-prognostic marker in these patients.MethodsThe urinary level of suPAR was measured in 146 patients, 94 pancreatic ductal adenocarcinoma and 52 chronic pancreatitis. Urine from 104 healthy subjects with similar age and gender distribution served as controls. suPAR levels were normalized with creatinine levels (suPAR/creatinine, ng/mg) to remove urine dilution effect.ResultsUrinary suPAR/creatinine values of pancreatic ductal adenocarcinoma patients were significantly higher (median 9.8; 25th-75th percentiles 5.3-20.7) than those of either healthy donors (median 0; 0-0.5) or chronic pancreatitis patients (median 2.7; 0.9-4.7). The distribution of values among cancer patients was widespread and asymmetric, 53% subjects having values beyond the 95th percentile of healthy donors. The values of suPAR/creatinine did not correlate with tumour stage, Ca19-9 or CEA levels. Higher values correlated with poor prognosis among non-resected patients at univariate analysis; multivariate Cox regression identified high urinary suPAR/creatinine as an independent predictor of poor survival among all cancer patients (odds ratio 2.10, p = 0.0023), together with tumour stage (stage III odds ratio 2.65, p = 0.0017; stage IV odds ratio 4.61, p < 0.0001) and female gender (odds ratio 1.85, p = 0.01).ConclusionsA high urinary suPAR/creatinine ratio represents a useful marker for the identification of a subset of patients with poorer outcome.

Motility Analysis of Pancreatic Adenocarcinoma Cells Reveals a Role for the Atypical |[zeta]| Isoform of Protein Kinase C in Cancer Cell Movement

The acquisition of an invasive and metastatic phenotype is accompanied by profound alterations of intracellular mechanisms controlling cell movement. Analysis of quantitative parameters of cell motility in cancer cells may help in the identification of intracellular signaling events determining invasion and metastasis. Here we developed a novel procedure of quantification of cell motility based on time-lapse video microscopy and digital image analysis. Three kinetic parameters, including area change, plasma membrane remodeling, and speed of linear movement, are quantified and combined in one single, time-normalized value we defined motility score (MS). Through calculation of the MS for various human pancreatic adenocarcinoma cell subclones, we identified clones characterized by low or high spontaneous motility in vitro. Analysis of the signaling mechanisms involved in the regulation of pancreatic adenocarcinoma cell motility showed that the atypical ζ isozyme of the serine-threonine protein kinase C (PKC) plays a critical role in maintaining a high MS in motile subclones, as demonstrated by the inhibitory effect of cell permeable peptides with sequence corresponding to the pseudosubstrate inhibitory region of the atypical ζ PKC. Other PKC isozymes, either classic or novel, seem not involved. Furthermore, biochemical analysis showed that in motile cells, ζ PKC is constitutively associated with the plasma membrane, whereas in nonmotile cells, ζ PKC is totally excluded from the plasma membrane. These data suggest that the disregulation of the function of atypical ζ PKC might be involved in the acquisition of an invasive and metastatic phenotype in pancreatic adenocarcinoma cells.

Somatostatin analogues and pancreatic fistulas.

Consideration is given to the characterisation of pancreatic fistulas (PFs), the rationale for their treatment, and supportive and specific treatment measures. Choice of treatment should be based not only on the percentage of closures achieved, but also on their time and cost. The combined use of parenteral nutrition (TPN) and somatostatin inhibits pancreatic secretion well; no therapy can inhibit it completely. Presumptive use of octreotide, a subcutaneous formulation of somatostatin, in patients undergoing elective pancreatic surgery, reduced postoperative complications, mainly PFs, in about 500 patients in two controlled double-blind clinical studies, confirming the use of octreotide both in prophylaxis and treatment. Octreotide has been tested on out-patients after a brief hospitalisation period, at a dose of 100 mg three times a day. Home treatment does not involve co-administration of TPN, thus lowering not only costs but also risks. Optimal doses and the types of fistula amenable to this therapy need to be established and we only use out-patient treatment for chronic low-output fistulas.

The role of surgery in the major early complications of severe acute pancreatitis.

The early complications of severe acute pancreatitis may constitute a dramatic clinical dilemma in the first 2 weeks of the disease, when the surgical approach is made even more difficult by failure to define the precise extent of the necrotic component of the disease. Moreover, the surgical indication itself is not always based on clear guidelines to which the clinician can refer, and this is due to factors of two types: (i) the intrinsic complexity of the pancreatitis syndrome in its early toxic stages and (ii) the difficulty in understanding the relevant information reported in the literature in this connection, which is often incomplete and based on confused terminology. While the surgical indication is universally accepted in the case of infection of the necrotic tissue (an event, however, which is by no means frequent in the early stages of severe pancreatitis), the development of multi-organ failure despite adequate intensive care is a potential indication which not all specialists go along with, at least not as regards the ideal timing of the intervention. Other surgical indications which have emerged are evidence of complete rupture of the main pancreatic duct and the presence of very extensive sterile necrosis. As things stand at present, however, we are witnessing a general tendency to postpone surgery, since delayed surgery is associated with a lower incidence of complications than is the case with early surgery. If, as is known, the role of surgery is aimed mainly at the treatment of superinfections and severe multi-organ failures, targeted antibiotic prophylaxis and earlier, more complete anti-enzymatic therapy may, as suggested by a number of pilot studies, offer a promising alternative to invasive procedures which are sometimes risky, though indispensable, in an attempt to save patients who would otherwise have no chance of survival.

Effects of choline-esterase inhibitor in experimental acute pancreatitis in rats. Preliminary results.

SummaryCholine-esterase inhibitor (Cl-INH), a regulatory alpha-glycoprotein, was administered at different dosages and intervals to rats with induced acute pancreatitis. When compared to controls, treated rats showed no significant differences in the severity of histopathological lesions, such as edema and single cell necrosis. On the other hand, both mortality and extent of massive necrosis were significantly affected by Cl-INH administration regardless of the dosages.