Christophe Müller

OBJECTIVE: To determine benefits of conservative versus surgical treatment in patients with necrotizing pancreatitis. SUMMARY BACKGROUND DATA: Infection of pancreatic necrosis is the most important risk factor contributing to death in severe acute pancreatitis, and it is generally accepted that infected pancreatic necrosis should be managed surgically. In contrast, the management of sterile pancreatic necrosis accompanied by organ failure is controversial. Recent clinical experience has provided evidence that conservative management of sterile pancreatic necrosis including early antibiotic administration seems promising. METHODS: A prospective single-center trial evaluated the role of nonsurgical management including early antibiotic treatment in patients with necrotizing pancreatitis. Pancreatic infection, if confirmed by fine-needle aspiration, was considered an indication for surgery, whereas patients without signs of pancreatic infection were treated without surgery. RESULTS: Between January 1994 and June 1999, 204 consecutive patients with acute pancreatitis were recruited. Eighty-six (42%) had necrotizing disease, of whom 57 (66%) had sterile and 29 (34%) infected necrosis. Patients with infected necrosis had more organ failures and a greater extent of necrosis compared with those with sterile necrosis. When early antibiotic treatment was used in all patients with necrotizing pancreatitis (imipenem/cilastatin), the characteristics of pancreatic infection changed to predominantly gram-positive and fungal infections. Fine-needle aspiration showed a sensitivity of 96% for detecting pancreatic infection. The death rate was 1.8% (1/56) in patients with sterile necrosis managed without surgery versus 24% (7/29) in patients with infected necrosis (P <.01). Two patients whose infected necrosis could not be diagnosed in a timely fashion died while receiving nonsurgical treatment. Thus, an intent-to-treat analysis (nonsurgical vs. surgical treatment) revealed a death rate of 5% (3/58) with conservative management versus 21% (6/28) with surgery. CONCLUSIONS: These results support nonsurgical management, including early antibiotic treatment, in patients with sterile pancreatic necrosis. Patients with infected necrosis still represent a high-risk group in severe acute pancreatitis, and for them surgical treatment seems preferable.

BACKGROUND: Mortality due to severe or necrotizing acute pancreatitis most often results from multiorgan dysfunction syndrome (MODS) occurring either early (within the first 14 days) or 2 weeks or more after the onset of symptoms due to septic complications. The aim of this study was to analyse the course of the disease in patients who died from severe acute pancreatitis. METHODS: Between January 1994 and August 2000 details of 263 consecutive patients with acute pancreatitis were entered prospectively into a database. All patients were treated in an intermediate or intensive care unit. RESULTS: The overall mortality rate was 4 per cent (ten of 263 patients). The mortality rate was 9 per cent (ten of 106) in patients with necrotizing disease. No patient died within the first 2 weeks of disease onset. The median day of death was 91 (range 15-209). Six patients died from septic MODS. Ranson score, Acute Physiology and Chronic Health Evaluation (APACHE) II score during the first week of disease, pre-existing co-morbidity, body mass index, infection and extent of necrosis were significantly associated with death (P < 0.01 for all parameters). However, only infection of the necrotic pancreas was an independent risk factor in the multivariate analysis. CONCLUSION: Early deaths in patients with severe acute pancreatitis are rare, mainly as a result of modern intensive care treatment. Nine of the ten deaths occurred more than 3 weeks after disease onset. Infection of pancreatic necrosis was the main risk factor for death.

The estimation of accuracy and applicability of QSAR and QSPR models for biological and physicochemical properties represents a critical problem. The developed parameter of "distance to model" (DM) is defined as a metric of similarity between the training and test set compounds that have been subjected to QSAR/QSPR modeling. In our previous work, we demonstrated the utility and optimal performance of DM metrics that have been based on the standard deviation within an ensemble of QSAR models. The current study applies such analysis to 30 QSAR models for the Ames mutagenicity data set that were previously reported within the 2009 QSAR challenge. We demonstrate that the DMs based on an ensemble (consensus) model provide systematically better performance than other DMs. The presented approach identifies 30-60% of compounds having an accuracy of prediction similar to the interlaboratory accuracy of the Ames test, which is estimated to be 90%. Thus, the in silico predictions can be used to halve the cost of experimental measurements by providing a similar prediction accuracy. The developed model has been made publicly available at http://ochem.eu/models/1 .

OriDB (http://www.oridb.org/) is a database containing collated genome-wide mapping studies of confirmed and predicted replication origin sites. The original database collated and curated Saccharomyces cerevisiae origin mapping studies. Here, we report that the OriDB database and web site have been revamped to improve user accessibility to curated data sets, to greatly increase the number of curated origin mapping studies, and to include the collation of replication origin sites in the fission yeast Schizosaccharomyces pombe. The revised database structure underlies these improvements and will facilitate further expansion in the future. The updated OriDB for S. cerevisiae is available at http://cerevisiae.oridb.org/ and for S. pombe at http://pombe.oridb.org/.

OBJECTIVE: beta-Cell regeneration has been proposed as a possible treatment for diabetes, but the capacity for new beta-cell formation in humans is yet unclear. In young rats, partial pancreatectomy prompts new beta-cell formation to restore beta-cell mass. We addressed the following questions: In adult humans: 1) Does partial pancreatectomy provoke new beta-cell formation and increased beta-cell mass? 2) Is beta-cell turnover increased after partial pancreatectomy? RESEARCH DESIGN AND METHODS: Protocol 1: human pancreatic tissue was collected from 13 patients who underwent two consecutive partial pancreas resections, and markers of cell turnover were determined in both tissue samples, respectively. Protocol 2: pancreas volumes were determined from abdominal computer tomography scans, performed in 17 patients on two separate occasions after partial pancreatectomy. RESULTS: Protocol 1: fasting glucose concentrations increased significantly after the 50% pancreatectomy (P = 0.01), but the fractional beta-cell area of the pancreas remained unchanged (P = 0.11). beta-Cell proliferation, the overall replication index (Ki67 staining), and the percentage of duct cells expressing insulin were similar before and after the partial pancreatectomy. The overall frequency of apoptosis (terminal deoxynucleotidyl transferase biotin-dUTP nick-end labeling) was slightly increased following the partial pancreatectomy (P = 0.02). Protocol 2: pancreatic volume was approximately 50% reduced to 35.6 +/- 2.6 ccm(3) by the partial pancreatectomy. The total pancreatic volume was unchanged after an interval of 247 +/- 160 days (35.4 +/- 2.7 ccm(3); P = 0.51). CONCLUSIONS: Unlike in rodents, a 50% pancreatectomy does not prompt beta-cell regeneration in adult humans. This explains the high incidence of diabetes after pancreatic resections. Such differences in beta-cell turnover between rodents and humans should be born in mind when evaluating new treatment options aiming to restore beta-cell mass in patients with diabetes.