The effect of isabelin, a sesquiterpene lactone from Ambrosia artemisiifolia on soil microorganisms and human pathogens.

Ambrosia artemisiifolia L. (common ragweed) is an invasive weed, which is well known for the strong allergenic effect of its pollen as well as for its invasiveness and impact in crop fields (e.g. causing yield losses). This species produces a broad range of sesquiterpenoids. In recent years, new bioactive molecules have been discovered in this plant, e.g. isabelin, a sesquiterpene dilactone. The bioactivity of isabelin has been already demonstrated on allergy-related receptors and its inhibitory effect on seeds of various plant species. Isabelin was tested for potential antimicrobial effects by using a selection of soil-borne bacteria and fungi and three human pathogens as model organisms. For the majority of microorganisms tested, no antimicrobial activity of isabelin was observed. However, isabelin revealed strong antimicrobial activity against the Gram-positive soil bacterium Paenibacillus sp. and against the Gram-positive, multidrug-resistant Staphylococcus aureus. The observed inhibitory activity of isabelin can enlighten the importance to study similar compounds for their effect on human pathogens and on soil and rhizosphere microorganisms.

Bioherbicidal activity of a germacranolide sesquiterpene dilactone from Ambrosia artemisiifolia L.

Ambrosia artemisiifolia L. (common ragweed) is an invasive plant whose allelopathic properties have been suggested by its field behaviour and demonstrated through phytotoxicity bioassays. However, the nature of the molecules responsible for the allelopathic activity of common ragweed has not been explored. The main objective of this study was to identify the phytotoxic molecules produced by A. artemisiifolia. A preliminary investigation has indicated that a methanol extract of A. artemisiifolia completely inhibited the germination of cress and radish. Semi-preparative fractionation of the methanol extract allowed separating of phytotoxic fraction which contained a single compound. The structure of this compound was elucidated by liquid chromatography-mass spectrometry (LC-MS)/MS, high-resolution mass spectral, nuclear magnetic resonance, and Fourier transform infrared spectra as sesquiterpene lactone isabelin (C15H16O4). The effect of pure isabelin was tested on four different weed species, confirming the inhibitory activity of molecule. The results indicate directions for the future studies about herbicidal specific activity of isabelin, as pure molecule or in the crude extract, as a potential candidate for biological weed control.

Cecostomy button for antegrade enemas: survey of 29 patients.

OBJECTIVE: This study evaluated the Trap-door button use (Cook Medical, Bloomington, IL) for antegrade enemas in children. METHODS: Since 2002, patients with fecal incontinence or encopresis and constipation underwent percutaneous cecostomy under laparoscopy using a button. Technical details are described. Age at surgery, operative time, hospital stay, diagnosis, indications for cecostomy, and duration of follow-up were recorded. A survey was proposed via a questionnaire that was sent to the patients. Patients wearing the button for less than 1 month were excluded from this evaluation. The survey concerned volume and frequency of enemas, difficulties encountered, benefits and disadvantages of this method, and assessment of the antegrade enemas in continence. RESULTS: Twenty-nine patients, 18 males and 11 females, aged 3 to 21 years (mean, 8.5 years) underwent laparoscopic Trap-door button placement. The indications for all the patients were intractable fecal incontinence in 24 cases and constipation with encopresis in 5 cases. Incontinence was because of myelomeningocele (n = 10), anorectal malformations (n = 11), caudal regression syndrome (n = 1), 22q11 syndrome (n= 1), and Hirschsprung disease with encephalopathy with convulsions (n = 1). Constipation with encopresis was because of sacrococcygeal teratoma (n = 1), cerebral palsy (n = 1), and acquired megarectum with psychiatric and social disorders (n = 3). A total of 26 cecostomy button placements and 3 sigmoidostomy button placements were successful with no intraoperative complication. The mean operative time was 25 minutes (10-40 minutes), and the hospital stay was 2.5 days (1-4 days). Twenty-two parents or patients answered the questionnaire. At the time of this survey, 2 patients had improved their fecal continence and had had the button removed. A mean of 4 weekly enemas was enough to improve fecal continence troubles (range, 1 daily to 1 for 2 weeks). The volume for enemas was 250 to 1000 mL (mean, 700 mL). The time required for the irrigation of the bowel by gravity took from 5 to 60 minutes (mean, 25 minutes) for 20 patients. Before surgery, 14 patients needed a diaper, day and night, and 6 needed sanitary protection. Soiling was a very significant inconvenience for all the patients. After surgery, only 5 patients needed a diaper (cerebral palsy, 22q11, cloacal malformation, myelomeningocele, bladder exstrophy) because of moderate results or urinary incontinence and continued soiling. Patients were asked to give an assessment (null = 0, bad = 1, fair = 2, good = 3, very good = 4). None of the patients felt there had been no changes or a bad result. There were 5 patients who felt they had an average result, 5 a good result, and 12 a very good result. The mean grade was 3.44 (17.2/20). A total of 3 patients had hypertrophic granulation tissue formation around the cecostomy button, and 12 had tiny leakage. CONCLUSION: Percutaneous placement of a cecostomy button under laparoscopic control is an easy and major complication-free procedure. The use of the Trap-door device by the patients or with the help of the parents for antegrade enemas is effective and satisfactory. It improves the quality of life and is reversible.