Opera and poison : a secret and enjoyable approach to teaching and learning chemistry

The storyline of operas, with historical or fictional characters, often include potions and poisons. This has prompted a study of the chemistry behind some operatic plots. The results were originally presented as a lecture given at the University of Minho in Portugal, within the context of the International Year of Chemistry. The same lecture was subsequently repeated at other universities as an invited lecture for science students and in public theaters for wider audiences. The lecture included a multimedia and interactive content that allowed the audience to listen to arias and to watch video clips with selected scenes extracted from operas. The present article, based on the lecture, demonstrates how chemistry and opera can be related and may also serve as a source of motivation and inspiration for chemistry teachers looking for alternative pedagogical approaches. Moreover, the lecture constitutes a vehicle that transports chemistry knowledge to wider audiences through examples of everyday molecules, with particular emphasis on natural products.The author is pleased to express his gratitude to Jorge Calado and Michael John Smith for useful discussions. The author also thanks the reviewers of the manuscript for their helpful comments and suggestions. Thanks are due to the Foundation for Science and Technology (FCT,Portugal), QREN and FEDER/EU for financial support through the research centers, CQ/UM PEst-C/QUI/UI0686/2011. Ciencia Viva, Portugal, is also acknowledged for financial support of the activities organized by the University of Minho during the International Year of Chemistry. The author also expresses his gratitude to Ana Paula Ferreira and Andre Cunha Leal from RTP Antena 2 who contributed immensely to the popularization of the lecture on which this paper is based on

Effect of Early Surgery vs Endoscopy-First Approach on Pain in Patients With Chronic Pancreatitis The ESCAPE Randomized Clinical Trial:The ESCAPE Randomized Clinical Trial

IMPORTANCE For patients with painful chronic pancreatitis, surgical treatment is postponed until medical and endoscopic treatment have failed. Observational studies have suggested that earlier surgery could mitigate disease progression, providing better pain control and preserving pancreatic function. OBJECTIVE To determine whether early surgery is more effective than the endoscopy-first approach in terms of clinical outcomes. DESIGN, SETTING, AND PARTICIPANTS The ESCAPE trial was an unblinded, multicenter, randomized clinical superiority trial involving 30 Dutch hospitals participating in the Dutch Pancreatitis Study Group. From April 2011 until September 2016, a total of 88 patients with chronic pancreatitis, a dilated main pancreatic duct, and who only recently started using prescribed opioids for severe pain (strong opioids for INTERVENTIONS There were 44 patients randomized to the early surgery group who underwent pancreatic drainage surgery within 6 weeks after randomization and 44 patients randomized to the endoscopy-first approach group who underwent medical treatment, endoscopy including lithotripsy if needed, and surgery if needed. MAIN OUTCOMES AND MEASURES The primary outcome was pain, measured on the Izbicki pain score and integrated over 18 months (range, 0-100 [increasing score indicates more pain severity]). Secondary outcomes were pain relief at the end of follow-up; number of interventions, complications, hospital admissions; pancreatic function; quality of life (measured on the 36-Item Short Form Health Survey [SF-36]); and mortality. RESULTS Among 88 patients who were randomized (mean age, 52 years; 21 (24%) women), 85 (97%) completed the trial. During 18 months of follow-up, patients in the early surgery group had a lower Izbicki pain score than patients in the group randomized to receive the endoscopy-first approach group (37 vs 49; between-group difference, -12 points [95% CI, -22 to -2]; P = .02). Complete or partial pain relief at end of follow-up was achieved in 23 of 40 patients (58%) in the early surgery vs 16 of 41 (39%)in the endoscopy-first approach group (P = .10). The total number of interventions was lower in the early surgery group (median, 1 vs 3; P <.001). Treatment complications (27% vs 25%), mortality (0% vs 0%), hospital admissions, pancreatic function, and quality of life were not significantly different between early surgery and the endoscopy-first approach. CONCLUSIONS AND RELEVANCE Among patients with chronic pancreatitis, early surgery compared with an endoscopy-first approach resulted in lower pain scores when integrated over 18 months. However, further research is needed to assess persistence of differences over time and to replicate the study findings

Should Helicobacter pylori be eradicated before starting long-term proton pump inhibitors?

Symptomatic gastro-oesophageal reflux disease is a common disorder characterized by pathological exposure of the distal oesophagus to acid. The management requires the control of symptoms, prevention of relapse and complications. Proton pump inhibitors are without doubt the most effective agents in the management of gastro-oesophageal reflux disease. In Helicobacter pylori-negative individuals the efficacy of ranitidine, but more pronounced of omeprazole, on the nocturnal intragastric acidity, is less than in Helicobacter pylori-positive patients. Curing the Helicobacter pylori infection in gastro-oesophageal reflux disease patients might, therefore, have the disadvantage of losing efficacy of antisecretory therapy. Conversely, several studies have shown that long-term use of proton pump inhibitors is associated with progression and worsening of body gastritis exclusively in Helicobacter pylori-positives. This observation makes Helicobacter pylori eradication indicated before starting long-term treatment with proton pump inhibitors for gastro-oesophageal reflux disease and other acid-related diseases. The data reported, so far, however, are not conclusive. The Federal Drugs Administration Advisory Committee concluded on available data, that there is no evidence that longterm proton pump inhibitors treatment leads to gastric atrophy, intestinal metaplasia or gastric cancer. Eradication of Helicobacter pylori infection might lead to reduction in the efficacy of antisecretory agents, but might prevent worsening of the gastric corpus gastritis. More data are needed to really answer these clinically relevant question

The role of acid suppressants in upper gastrointestinal ulcer bleeding

Re-bleeding and mortality remain significant in peptic ulcer haemorrhage despite the widespread use of endoscopic therapy. The acidic gastric environment interferes with coagulation. In vitro studies show that an intragastric pH of above 6 results in normal blood coagulation and platelet function. Because of induced tachyphylaxis, H(2)-receptor antagonists are not able to maintain a high pH. In addition, in randomized trials using H(2)-receptor antagonists, there was no reduction in re-bleeding and mortality. High-dose intravenous proton pump inhibitors are capable of maintaining a pH above 6. Four randomized trials, using high-dose intravenous proton pump inhibitors, significantly improved the outcome (in terms of a reduction in re-bleeding and surgery) in patients with peptic ulcer haemorrhage. Mortality was, however, not reduced. The additional effect of acid-suppressant agents after successful endoscopic therapy is limited to the reduction of re-bleeding and need for surgery, with no effect on mortalit

Cure of duodenal ulcer associated with eradication of Helicobacter pylori

50 patients with intractable duodenal ulcer were randomly assigned to 4 weeks of treatment with colloidal bismuth subcitrate (CBS) alone (26 patients) or with amoxicillin and metronidazole (24 patients). 5 patients (all on triple therapy) withdrew because of side-effects. In 17 of the 45 patients who completed the treatment, Helicobacter pylori was eradicated, and there was no ulcer relapse during the first 12 months of follow-up. The ulcer relapse rate was significantly higher (17 of 21 [89%]) among patients who remained positive for H pylori. 9 patients who remained positive for H pylori and had ulcer relapses within 6 months of treatment with CBS alone, were subsequently given triple therapy. 7 of the 9 showed H pylori eradication and no relapses within the next 12 months. The 2 patients still H pylori-positive after triple therapy had further ulcer relapses. H pylori eradication, without altering acid output, will become the mainstay of duodenal ulcer treatment because it cures the diseas

Endoscopic and surgical management of bile duct injury after laparoscopic cholecystectomy

Laparoscopic cholecystectomy has become the first choice of management for symptomatic cholecystolithiasis. While it is associated with decreased postoperative morbidity and mortality, bile duct injuries are reported to be more severe and more common (0-2.7%), when compared to open cholecystectomy (0.2-0.5%) [New Engl. J. Med. 234 (1991) 1073; Am. J. Surg. 165 (1993) 9; Surg. Clin. N Am. 80 (2000) 1127]. These bile duct injuries include leaks, strictures, transection and removal of (part of) the duct, with or without vascular damage. Bile duct injury might be due to misidentification of the biliary tract anatomy due to acute cholecystitis, large impacted stones, short cystic duct, anatomical variations, but also due to technical errors leading to bleeding with subsequent clipping and coagulation trauma [Ann. Surg. 237 (2003) 460]. Early recognition and adequate multidisciplinary approach is the cornerstone for the optimal final outcome. Suboptimal management of injuries often leads to more extensive damage to the biliary tree and its vasculature with as consequences biliary peritonitis, sepsis, abscesses, multiple organ failure, a more difficult (proximal) reconstruction and in the long run, secondary biliary cirrhosis, and liver failure. Despite increasing experience in performing laparoscopic cholecystectomy, the frequency of bile duct injuries has not decreased [Ann. Surg. 234 (2001) 549]. Therapy encompasses endoscopic stenting, percutaneous transhepatic dilatation (PTCD) and surgical reconstructio

Current guidelines for the eradication of Helicobacter pylori in peptic ulcer disease

Pharmacological suppression of gastric acid secretion has traditionally been the most rational approach to healing ulcers successfully. However, ulcers initially healed using antisecretory therapy have a tendency to relapse after treatment is withdrawn. This tendency is altered definitively by eradication of Helicobacter pylori. Antimicrobial therapy should be given to all patients with documented duodenal and gastric ulcer associated with H. pylori infection. The optimal therapeutic regimen to eradicate H. pylori is still not completely clear. The requirement for treatment to be effective in more than 90% of patients makes monotherapy and dual therapy inappropriate. Bismuth-based triple therapy (bismuth, tetracycline and metronidazole) is highly efficacious if the H. pylori strain is sensitive to metronidazole and the patient is compliant, but adverse effects often occur. Triple therapy consisting of omeprazole and 2 antimicrobials (clarithromycin and/or amoxicillin and/or metronidazole) and quadruple therapy (bismuth-based triple therapy plus omeprazole) are both very effective and patient compliance may be better because of the shortened (1 week) course. Preliminary data indicate that the efficacy of the regimen is not influenced by imidazole resistance. Eradication of H. pylori prevents complications and relapse of peptic ulcer disease and is a cost-effective option compared with maintenance acid-suppressive therap

Helicobacter pylori eradication and gastric cancer: when is the horse out of the barn?

Helicobacter pylori infection is a major risk factor for gastric cancer development. Therefore, H. pylori eradication may be an important approach in the prevention of gastric cancer. However, long-term data proving the efficacy of this approach are lacking. This report describes two patients who developed gastric cancer at, respectively, 4 and 14 years after H. pylori eradication therapy. These patients were included in a study cohort of H. pylori-infected subjects who received anti-H. pylori therapy during the early years of development of H. pylori eradication therapy and underwent strict endoscopic follow-up for several years. In both patients, gastric ulcer disease and premalignant gastric lesions, i.e., intestinal metaplasia at baseline and dysplasia during follow-up, were diagnosed before gastric cancer development. These case reports demonstrate that H. pylori eradication does not prevent gastric cancer development in all infected patients after long-term follow-up. In patients with premalignant gastric lesions, in particular in patients with a history of gastric ulcer disease, adequate endoscopic follow-up is essential for early detection of gastric neoplasi