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BE-14106 is a macrocyclic lactam with an acyl side chain previously identified in a marine-derived Streptomyces sp. The gene cluster for BE-14106 biosynthesis was cloned from a Streptomyces strain newly isolated from marine sediments collected in the Trondheimsfjord (Norway). Bioinformatics and experimental analyses of the genes in the cluster suggested an unusual mechanism for assembly of the molecule. Biosynthesis of the aminoacyl starter apparently involves the concerted action of a distinct polyketide synthase (PKS) system and several enzymes that activate and process an amino acid. The resulting starter unit is loaded onto a second PKS complex, which completes the synthesis of the macrolactam ring. Gene inactivation experiments, enzyme assays with heterologously expressed proteins, and feeding studies supported the proposed model for the biosynthesis and provided new insights into the assembly of macrolactams with acyl side chain.

Background: To investigate the effect of cervical laser conisation (CLC) or loop electrosurgical excision procedure (LEEP) on the outcome of subsequent pregnancies. Methods. Multi-centre, retrospective, case-control study, which included a cohort of 742 women, who, after treatment with LEEP or CLC, gave birth or suffered second trimester miscarriage. Control women (n=742) were extracted from the respective hospital birth registries and matched by age and parity. Outcome measures were perinatal mortality, length of gestation, birth weight and preterm premature rupture of membranes (pPROM)., Results: There was no significant difference in perinatal mortality among women treated with LCL or LEEP compared to controls, 6/742 versus 2/742: odds ratio (OR)=3.1 (95% CI: 0.6-15.2). Excluding second trimester miscarriages, ORs for giving birth before week 37, 32 and 28 after conisation compared to the controls were 3.4 (95% CI: 2.3-5.1), 4.6 (95% CI: 1.7-12.5), and 12.4 (95% CI: 1.6-96.1), respectively, after adjusting for smoking habits during pregnancy, marital status and educational level. Adjusted ORs of birth weight <2,500, <1,500 and <1,000 g after conisation compared to controls were 3.9 (95% CI: 2.4-6.3), 4.4 (95% CI: 1.5-13.6), and 10.4 (95% CI: 1.3-82.2), respectively. The adjusted OR for pPROM was 10.5 (95% CI: 3.7-29.5)., Conclusion: Treatment by CLC and LEEP increases the risk of preterm delivery, low birth weight and pPROM in subsequent pregnancies.

Background: Budesonide is a corticosteroid with high topical anti-inflammatory activity and low systemic activity due to rapid inactivation. We have assessed the efficacy and safety of an oral controlled ileal release (CIR) preparation of budesonide for maintenance of remission in patients with ileal or ileocaecal Crohn's disease., Methods: In a double-blind, multicentre trial, 75 patients in clinical remission (Crohn's Disease Activity Index, CDAI, < or = 150) were randomly assigned to receive placebo, budesonide 3 mg or budesonide 6 mg daily for 12 months. Trial drugs were given at a fixed dose and without concomitant medication. The primary outcome measure was relapse, defined as a CDAI > 150 together with an increase of at least 60 units from entry. A patient was also considered to have a relapse if withdrawn from the study due to clinical deterioration, whether or not a CDAI value could be calculated at that time., Results: There were no statistically significant differences in the relapse rate at any time-point throughout the study. By 12 months the proportion of patients having relapsed were 48, 46 and 60% in those patients treated with budesonide 6 mg, 3 mg and placebo, respectively (N.S.). Treatments were well tolerated, and the proportion of patients with suppressed adrenal function (according to predetermined criteria) were 50% (6 mg), 26% (3 mg) and 17% (placebo) (P = 0.096)., Conclusions: In the present study, relapse rate and time to relapse were similar in the patients treated with budesonide CIR, 6 mg daily or 3 mg daily or with placebo, throughout 12 months. This is in contrast to the two previous trials with identical design, where a significant effect of budesonide CIR in prolonging the median time to relapse was found. Possible reasons for the negative results of the present study include small sample size, and the fact that there was a high placebo response.

Background: The cyclo-oxygenase inhibitor indomethacin induces a pattern of gastrointestinal injury in the rat that is site-dependent. This study compared the extent of injury to different regions of the rat intestine (small intestine, caecum and colon) with the corresponding changes in arachidonic acid metabolism in these areas, following long-term, low-dose indomethachin., Methods: Rats (eight per group) received either indomethacin (3 mg.kg/day) or control diet for either 6 or 12 weeks. At termination animals were bled, examined both macroscopically and microscopically for ulcers, and assayed for blood thromboxane B2, intestinal tissue prostaglandin E2 content and production of leukotriene B4. In a further eight animals luminal indomethacin concentrations from the small intestine, caecum and colon were measured following 6 weeks of chronic drug ingestion., Results: At 6 weeks, macroscopic ulcers were observed in 2/8 (small intestine), 3/8 (caecum) and 1/8 (colon) animals. The corresponding ratios at 12 weeks were 5/8, 8/8 and 0/8. In control animals, a site-dependent gradient of the prostaglandin E2 concentration was found. In indomethacin-dosed animals the intestinal prostaglandin E2 content was reduced significantly in the caecum at 6 weeks, and in all tissues at 12 weeks. An increased leukotriene B4 production was observed in the caecum only, at 12 weeks (P < 0.01), and the blood thromboxane B2 was reduced at both time points (P < 0.05)., Conclusion: There is a site-dependent gradient of the prostaglandin E2 concentration in the rat intestine. The rat caecum is particularly sensitive to long-term low-dose indomethacin, both in terms of chronic intestinal inflammation and changes in prostanoid metabolism. This site-dependent degree of injury may be associated with a local cyclo-oxygenase inhibition.

Background: In view of the association between non-steroidal anti-inflammatory drugs (NSAIDs) and microvascular injury in the intestine, this study investigated the procoagulant changes in cultured human umbilical vein endothelial cells (HUVEC) when exposed to indomethacin either alone or in the presence of bacterial lipopolysaccharide (LPS)., Methods: Confluent HUVEC cultures were cultured for 1, 6, 12, and 24 h in the presence of LPS (10 micrograms/ml) with or without indomethacin (1-100 microM). After incubation, supernatants were analysed for 6-keto-prostaglandin (PG) F1 alpha and PGE2 content, whereas cells were freeze-fractured and assayed in a one-stage clotting assay for the expression of procoagulant activity (PCA)., Results: LPS induced a significant expression of PCA at 6, 12, and 24 h, with a significantly increased production of 6-keto-PGF1 alpha, whereas the increased PGE2 production was much less pronounced. Indomethacin alone induced a time-dependent PCA response; when coincubated with LPS the PCA response was greater than that produced by either indomethacin or LPS alone. Indomethacin totally abolished the synthesis of antithrombotic eicosanoids., Conclusion: Indomethacin induces PCA in HUVEC and augments LPS-induced PCA, while it abolishes the antithrombotic prostanoid response in these cells. These observations may be relevant to the microvascular injury and thrombosis observed in NSAID enteropathy.

Background/aims: Gastrointestinal injury induced by nonsteroidal anti-inflammatory drugs includes smooth muscle contraction, endothelial cell injury, and neutrophil infiltration. The aim of this study was to correlate early morphological changes with those in the metabolism of arachidonic acid., Methods: Rats administered a single oral dose of indomethacin (15 mg/kg) or vehicle were killed and their intestines perfusion-fixed at 1, 2, 3, 6, and 48 hours after dosage. Serial sections of affected small intestine were immunostained for neutrophils, macrophages, actin, and fibrinogen. In addition, rats receiving either indomethacin (15 mg/kg) or vehicle were killed at 1 and 6 hours after dosage; blood and small intestinal tissue were assayed for blood thromboxane B2, intestinal tissue prostaglandin E2, and the intestinal production of leukotriene B4., Results: At 2-6 hours, both intravascular and extravascular fibrin deposition were evident at the villus tip, and vertical alignment of villus smooth muscle cells was prominent. Significant neutrophil infiltration associated with a significant increase in leukotriene production was observed 6 hours after dosage. The extracted prostaglandin E2 content that was suppressed at 1 hour had recovered by 6 hours, whereas the blood thromboxane B2 levels were suppressed throughout the experiment., Conclusions: This study identifies an early neutrophil-independent phase of indomethacin-induced enteropathy that involves rapid cyclooxygenase inhibition and both microvascular and smooth muscle changes.

Arachidonic acid (AA) might be released from a number of different intracellular pools. This aspect was studied by sequential incorporation of 3H- and 14C-AA during 24 h in rabbit colonic biopsies in culture. Mucosal explants were subjected to 3H-AA (0-6 h) and 14C-AA (6-24 h) followed by a 2-h washout. Lipid extraction of biopsies revealed a distinct pattern where 3H, in relative terms, dominated in phosphatidylinositol (PI) and phosphatidylethanolamine (PE) and 14C was more abundant in neutral lipids, whereas the remaining lipids had equal proportions of labellings. When stimulating double labelled biopsies with 1 microM phorbol 12-myristate 13-acetate (PMA), 10 micrograms/ml A23187 and a combination thereof, the 14C-labelling was in general released in larger amounts, i.e. a maximum of 7.5% with the combined drugs vs 5% for 3H. However, the relative release of 3H increased upon stimulation especially for PMA + A23187. The release of labelling was directly coupled to a stimulation dependent production of PGE2 in the order PMA less than A23187 less than PMA + A23187, maximum release = 8.2 +/- 2.4 ng/h and 3 biopsies. This study shows the existence of different AA-pools, where PI and PE (3H-labelling) appears to have a slow turnover and representing a terminus in a redistribution chain and where neutral lipids (14C-labelling) have a more rapid turnover. Upon stimulation more AA appears to be recruited from pools with slow turnover.

A gastric mucosa in vitro model for studies of experimental Helicobacter pylori infections has been developed. Biopsy specimens were taken from pig gastric mucosa, infected with H. pylori, and cultured for up to 72 h. To determine the degree of H. pylori adhesion, specimens were vigorously rinsed by vortexing five times before measuring viable count and urease activity. The results showed that it is possible to culture pig gastric mucosa in vitro with maintained viability for at least 72 h. According to the viable count, the bacteria survived and multiplied during the whole culture period. The percentage viable H. pylori in the specimens after rinsing and the urease activity increased with time of culture. The results indicate that the bacteria in the gastric specimens were viable after 72 h and that there was a time-dependent increase in bacterial adhesion to the specimens. This in vitro gastric mucosa model promises to be an applicable and reproducible method, with high capacity, for both pathogenic and mechanistic studies of H. pylori infection.