Emergency endoscopy during the SARS-CoV-2 pandemic in the north of Italy. Experience from St. Orsola University Hospital—Bologna

No abstract availabl

Effect of antithrombotic therapy on postoperative outcome of 538 consecutive emergency laparoscopic cholecystectomies for acute cholecystitis. Two Italian center’s study

The risk of developing hemorrhagic complications during or after emergency cholecystectomy (EC) for acute cholecystitis (AC) in patients with antithrombotic therapy (ATT) remains uncertain. In this double-center study, we evaluated post-operative outcomes in patients with ATT undergoing EC. We retrospectively evaluated 538 patients who underwent laparoscopic EC for AC between May 2015 and December 2019 at two referral centers. 89 of them (17%) were on ATT. We defined postoperative complication rates, including bleeding, as our primary outcome. Mortality was higher in the ATT group. Morbidity was higher in the ATT group as well; however, the difference was not statistically significant. 12 patients (2%) experienced intraoperative blood loss over 500 ml and ten (2%) had postoperative bleeding complications. Two patients (< 1%) experienced both intraoperative and postoperative bleeding. On multivariate analysis, ATT was not significantly associated with worse postoperative outcomes. Antithrombotic therapy is not an independently associated factor of severe postoperative complications (including bleeding) or mortality. However, these patients still represent a challenging group and must be carefully managed to avoid postoperative bleeding complications

The Role of Hydrogen Bonds in the Stabilization of Silver-Mediated Cytosine Tetramers

Peer reviewe

Atypical presentation of acute idiopathic megacolon in a 14-year-old patient

In clinical practice the term "megacolon" is used to indicate a marked dilatation of the cecum and the sigmoid colon (>12 and 6.5 cm, respectively) (1). From a clinical standpoint, a megacolon can be classified as chronic or acute depending on its clinical presentation. Chronic megacolon typically refers to a congenital disorder in which the enteric nervous system (ENS) supplying the colon does not develop properly, thereby leaving the distal segments of the viscus without myenteric and submucosal ganglia (i.e. Hirschsprung's disease) (2). Other cases of non-aganglionic chronic megacolon can be secondary to variety of conditions such as Chagas' disease and neurodegenerative diseases (e.g. Parkinson's and Alzheimer's diseases), leading to or associated with ENS abnormalities (3). The acute form of megacolon, also referred to as Ogilvie's syndrome, is characterized by a predominant involvement of the cecum and right colon usually affecting elderly patients undergoing surgery (e.g. orthopedic procedures) or taking medications altering gut motility (e.g. opioids or antidepressants) (4). Some forms of acute megacolon, however, can be idiopathic in origin since no underlying etiology can be identified. Patients with acute idiopathic megacolon usually have a longstanding history of constipation, often accompanied by laxative abuse, and their clinical presentation is characterized by abdominal distension and severe pain with radiological evidence of stool impacted in the colon and rectum (1, 4). The case herein reported represents an unusual form of acute idiopathic megacolon characterized by massive descending and sigmoid colon distension complicated with a volvulus in a 14-year-old boy with no Hirschsprung's disease. In addition, just to increase the peculiarity of this case report, the patient had an unremarkable clinical record, and never suffered from chronic constipation in the past

Bibliografía histórica sobre la Ciencia y la Técnica en España. 1997

Repertori de bibliografia històrica sobre la ciència i la tècnica a Espanya editada en 1994. //.Repertorio de bibliografía histórica sobre la ciencia y la técnica en España editada en 1994

Stepwise Catalytic Mechanism via Short-Lived Intermediate Inferred from Combined QM/MM MERP and PES Calculations on Retaining Glycosyltransferase ppGalNAcT2

The glycosylation of cell surface proteins plays a crucial role in a multitude of biological processes, such as cell adhesion and recognition. To understand the process of protein glycosylation, the reaction mechanisms of the participating enzymes need to be known. However, the reaction mechanism of retaining glycosyltransferases has not yet been sufficiently explained. Here we investigated the catalytic mechanism of human isoform 2 of the retaining glycosyltransferase polypeptide UDP-GalNAc transferase by coupling two different QM/MM-based approaches, namely a potential energy surface scan in two distance difference dimensions and a minimum energy reaction path optimisation using the Nudged Elastic Band method. Potential energy scan studies often suffer from inadequate sampling of reactive processes due to a predefined scan coordinate system. At the same time, path optimisation methods enable the sampling of a virtually unlimited number of dimensions, but their results cannot be unambiguously interpreted without knowledge of the potential energy surface. By combining these methods, we have been able to eliminate the most significant sources of potential errors inherent to each of these approaches. The structural model is based on the crystal structure of human isoform 2. In the QM/MM method, the QM region consists of 275 atoms, the remaining 5776 atoms were in the MM region. We found that ppGalNAcT2 catalyzes a same-face nucleophilic substitution with internal return (SNi). The optimized transition state for the reaction is 13.8 kcal/mol higher in energy than the reactant while the energy of the product complex is 6.7 kcal/mol lower. During the process of nucleophilic attack, a proton is synchronously transferred to the leaving phosphate. The presence of a short-lived metastable oxocarbenium intermediate is likely, as indicated by the reaction energy profiles obtained using high-level density functionals