José Lopez

Helicobacter pylori eradication prevents recurrence from peptic ulcer haemorrhage.

Background Successful eradication of Helicobacter pylori infection clearly modifies the natural history of peptic ulcer disease and prevents further recurrences of duodenal and gastric ulcers. However, there are few prospective studies about actual rates of rebleeding after H. pylori eradication, a highly relevant aspect of management as re‐infection, relapse of ulcer disease for other reasons (i.e. antiinflammatory agents) or idiopathic ulcers unrelated to H. pylori may develop and cause further bleeding episodes. Objective To determine the incidence of bleeding episodes after eradication of H. pylori infection in patients who had bled from an H. pylori‐positive peptic ulcer. Participants and interventions H. pylori‐positive patients who bled from a gastric or duodenal ulcer were treated with appropriate triple and/or quadruple therapy. H. pylori eradication was confirmed by urea breath test 4 weeks after treatment. Patients received no further treatment but were followed clinically and additional urea breath tests were performed every 6 months. Endoscopy with antral and corpus biopsies and urea breath test were repeated as soon as patients manifested any dyspeptic symptoms that might signal recurrence. Results A total of 103 patients with bleeding duodenal ulcer were included in the study; H. pylori was successfully eradicated in 93 of these patients, who were followed for a median interval of 27 months. The yearly re‐infection rate was calculated to be 0.6%. There were no instances of rebleeding in any patients during the follow‐up period. Conclusions Even after prolonged follow‐up, successful H. pylori eradication prevents rebleeding. Eur J Gastroenterol Hepatol 12:733‐737

COMPOSITION AND BIOLOGICAL ACTIVITY OF THE ESSENTIAL OIL OF PERUVIAN LANTANA CAMARA

The composition of the essential oil from Lantana camara L. (Verbenaceae) obtained by hydrodistillation of the aerial parts was examined by GC, GC/ MS, and 13C-NMR. The GC analysis showed that carvone is the most abundant monoterpene 75.9%, together with limonene 16.9%, accounting for 92.8% of the oil. The major components were also tested by 13C-NMR analysis of the essential oil. The L. camara oil was assayed against several microorganisms, showing moderate antibacterial activity against the human pathogen Staphylococcus aureus (MIC 200 µg/ml). High antioxidant activity evaluated by the Trolox equivalent antioxidant capacity assay (TEAC) was found (29.0 mmol Trolox/kg) and relative low anti-inflammatory activity due to its weak ability for inhibiting lipoxygenase (IC 50 = 81.5 µg/ml).

The impact of delaying gastric emptying by either meal substrate or drug on the [13C]-urea breath test

Objective:Optimal [13C]-urea breath test (UBT) conditions for diagnosis of Helicobacter pylori infection are still being fine-tuned. In the present study we investigated the impact of delaying gastric emptying by different meal substrates or L-DOPA, a drug known to induce gastric stasis, on the performance of the [13C]-UBT.Methods:A total of 115 patients participated in the study. On two consecutive days, participants ingested [13C]-urea (100 mg) 10 min after either 270 ml of a mixed formula meal (1 Kcal/ml) or an equivalent amount of tap water. In 11 participants two additional tests were performed with or without oral 500 mg L-DOPA given 30 min before [13C]-urea load. The 13C/12C ratio in a basal breath sample was compared with ratios in samples collected 30 and 60 min after [13C]-urea. Histological assessment of H. pylori presence in antral biopsy served as reference standard.Results:Formula UBT showed excellent specificity (100% at 30 and 60 min) and good sensitivity (97% at both time intervals), whereas water UBT had the same specificity but slightly lower sensitivity (94% at 30 min and 73% at 60 min). In formula UBT, 13C/12C ratios were higher at 60 min than at 30 min (21.7 ± 2 vs 17.7 ± 1.8‰ respectively, p < 0.01, whereas in water UBT 13C/12C ratios were higher at 30 min than at 60 min (13.9 ± 1.5 vs 8.4 ± 0.09‰ respectively, p < 0.01). Pretreatment with L-DOPA did not modify either the sensitivity or the specificity of the UBT.Conclusions:The performance of the [13C]-urea with a formula meal may not be improved by pharmacologically delaying gastric emptying. A short, water-based test may be a sensible approach to worldwide standardization of the [13C]-UBT for H. pylori infection.

Partial Synthesis of (–)-11,12-Dinordriman-8-one and the (–)-Enantiomer of Polywood†

A chiral sequiterpene diol 6, readily available from the natural product polygodial (4), has been used for the first partial synthesis of the title compounds.

CHEMICAL COMPOSITION OF THE ESSENTIAL OIL OF Xenophyllum poposum

0009-3130/11/4606-0988 2011 Springer Science+Business Media, Inc. 1) Departamento de Ciencias Quimicas y Farmaceuticas, Universidad Arturo Prat, Casilla 121, Iquique, Chile, fax: 0056 57 394365, e-mail: julio.benites@unap.cl; 2) INETI, Instituto Nacional de Engenharia Tecnologia e Inovacao I. P., Departamento de Tecnologia de Industrias Quimicas, Estrada do Paco do Lumiar, 1649-038 Lisboa, Portugal, fax: 351 217168100, e-mail: cristina.moiteiro@ineti.pt. Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 838–839, November–December, 2010. Original article submitted July 8, 2009. Chemistry of Natural Compounds, Vol. 46, No. 6, 2011

THE PREPARATION OF OXYGENATED DERIVATIVES OF AMBROX AND ISOAMBROX FROM DRIMENOL

The preparation of oxygenated derivatives of ambrox and isoambrox is described. The compounds 7α-hydroxy-isoambrox, 7β-hydroxy-isoambrox, 7αhydroxy-ambrox, 7β-hydroxy-ambrox, 7-oxo-isoambrox and 7-oxo-ambrox have been synthesized from (-)-drimenol, readily available from the bark of Drimys winteri. The structures of the products were determined mainly by spectroscopic methods.