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Biomedical subjects

P Marteau

Publications and source records attributed to P Marteau.

At least 19 recordsLinked to original sources

Antioxidant effects of metronidazole in colonic tissue.

Reactive oxygen species, primarily generated in the mitochondria, contribute to tissue injury in inflammatory bowel diseases. The efficacy of metronidazole (MTZ) in some situations of inflammatory bowel disease may result not only from its antibiotic effect, but also from an antioxidant effect. We evaluated, under physiologic conditions, the antioxidant potential of MTZ on the biomarkers of oxidative damage to proteins (protein carbonyls), lipids (malondialdehyde), and the levels of antioxidant defense (glutathione) in the small bowel, large bowel, and liver of control and MTZ-treated rats. Basal levels of protein carbonyls and malondialdehyde were significantly higher in the colon compared with those in the small intestine, whereas glutathione levels were quite similar along the bowel. MTZ reduced significantly the colonic oxidative damage to proteins without any side effect in the liver. This is the first evidence of an antioxidant effect of MTZ on oxidative protein damage in the colon under physiologic conditions.

Animals↗

Review article: the role of bacteria in onset and perpetuation of inflammatory bowel disease.

We review the evidence that strongly suggests a role of the intestinal microbiota in the onset and perpetuation of inflammatory bowel disease (IBD). Experimental studies consisted of suppressing micro-organisms from the microbiota (using germ-free or gnotoxenic animals or antibiotics), introducing new micro-organisms or microbial components (e.g. probiotics, CpG-DNA) or selectively increasing some endogenous bacteria (e.g. using prebiotics). Intervention studies were performed in patients or animal models of spontaneous or chemically-induced colitis. Information was also obtained from observational studies that described the composition of the faecal and mucosal microbiota at various stages of the disease process and in controls. Many have used culture-independent techniques that identify bacteria based on the nucleic acid sequence of ribosomal RNA molecules. Microbiota in patients with IBD seem to be characterized by high concentrations of bacteria in contact with the mucosa, instability, the presence of high numbers of unusual bacteria and sometimes a reduction in the biodiversity. Studies searching for a generalized or localized dysbiosis in IBD are discussed, as well as those trying to identify bacterial molecules and receptors, which may be implicated in triggering the inflammatory process.

Bacterial Infections↗

Temperature gradient gel electrophoresis of fecal 16S rRNA reveals active Escherichia coli in the microbiota of patients with ulcerative colitis.

Previous studies of the endogenous microbiota in patients with ulcerative colitis (UC) have not taken bacterial activity into account, yet bacteria with high transcriptional activity might have a more important pathophysiological role than inactive bacteria. We therefore analyzed the biodiversity of active bacteria in the fecal microbiota of UC patients, in comparison with that of healthy subjects. Feces were collected from nine patients with active UC and from nine healthy controls. Total DNA and RNA were extracted, and 16S ribosomal DNA and RNA were amplified by PCR and reverse transcription-PCR, respectively. Amplification products were compared by means of temporal temperature gradient gel electrophoresis (TTGE). Bands of interest were excised, sequenced, and identified by comparison with the GenBank database (NCBI). The dominant-species diversity based on RNA-derived TTGE profiles was significantly lower for UC patients than for healthy controls (P = 0.01). The mean similarity index between the "present" and "active" microbiota was 74% +/- 18% for UC patients. Comparison of the individual "active" microbiota identified a band that was present for eight UC patients and only two controls (89% versus 22%; P = 0.008). The band was sequenced for 6 patients and always corresponded to Escherichia coli. The biodiversity of active bacteria in the dominant fecal microbiota of patients with UC is lower than that of healthy subjects. E. coli is more represented in the active microbiota of UC patients. The possible pathophysiological role of this difference remains to be determined.

Adult↗

European evidence based consensus on the diagnosis and management of Crohn's disease: current management.

This second section of the European Crohn's and Colitis Organisation (ECCO) Consensus on the management of Crohn's disease concerns treatment of active disease, maintenance of medically induced remission, and surgery. The first section on definitions and diagnosis includes the aims and methods of the consensus, as well as sections on diagnosis, pathology, and classification of Crohn's disease. The third section on special situations in Crohn's disease includes postoperative recurrence, fistulating disease, paediatrics, pregnancy, psychosomatics, extraintestinal manifestations, and alternative therapy for Crohn's disease.

Adrenal Cortex Hormones↗

Ineffectiveness of Lactobacillus johnsonii LA1 for prophylaxis of postoperative recurrence in Crohn's disease: a randomised, double blind, placebo controlled GETAID trial.

BACKGROUND AND AIMS: Early endoscopic recurrence is frequent after intestinal resection for Crohn's disease. Bacteria are involved, and probiotics may modulate immune responses to the intestinal flora. Here we tested the probiotic strain Lactobacillus johnsonii LA1 in this setting. PATIENTS AND METHODS: This was a randomised, double blind, placebo controlled study. Patients were eligible if they had undergone surgical resection of <1 m, removing all macroscopic lesions within the past 21 days. Patients were randomised to receive two packets per day of lyophilised LA1 (2 x 10(9) cfu) or placebo for six months; no other treatment was allowed. The primary endpoint was endoscopic recurrence at six months, with grade >1 in Rutgeerts' classification or an adapted classification for colonic lesions. Endoscopic score was the maximal grade of ileal and colonic lesions. Analyses were performed primarily on an intent to treat basis. RESULTS: Ninety eight patients were enrolled (48 in the LA1 group). At six months, endoscopic recurrence was observed in 30/47 patients (64%) in the placebo group and in 21/43 (49%) in the LA1 group (p = 0.15). Per protocol analysis confirmed this result. Endoscopic score distribution did not differ significantly between the LA1 and placebo groups. There were four clinical recurrences in the LA1 group and three in the placebo group. CONCLUSION: L johnsonii LA1 (4 x 10(9) cfu/day) did not have a sufficient effect, if any, to prevent endoscopic recurrence of Crohn's disease.

Adult↗

Reduced diversity of faecal microbiota in Crohn's disease revealed by a metagenomic approach.

BACKGROUND AND AIM: A role for the intestinal microbial community (microbiota) in the onset and chronicity of Crohn's disease (CD) is strongly suspected. However, investigation of such a complex ecosystem is difficult, even with culture independent molecular approaches. METHODS: We used, for the first time, a comprehensive metagenomic approach to investigate the full range of intestinal microbial diversity. We used a fosmid vector to construct two libraries of genomic DNA isolated directly from faecal samples of six healthy donors and six patients with CD. Bacterial diversity was analysed by screening the two DNA libraries, each composed of 25,000 clones, for the 16S rRNA gene by DNA hybridisation. RESULTS: Among 1190 selected clones, we identified 125 non-redundant ribotypes mainly represented by the phyla Bacteroidetes and Firmicutes. Among the Firmicutes, 43 distinct ribotypes were identified in the healthy microbiota, compared with only 13 in CD (p<0.025). Fluorescent in situ hybridisation directly targeting 16S rRNA in faecal samples analysed individually (n=12) confirmed the significant reduction in the proportion of bacteria belonging to this phylum in CD patients (p<0.02). CONCLUSION: The metagenomic approach allowed us to detect a reduced complexity of the bacterial phylum Firmicutes as a signature of the faecal microbiota in patients with CD. It also indicated the presence of new bacterial species.

Adolescent↗

Malnutrition in adults with cystic fibrosis.

OBJECTIVE: To determine the prevalence and clinical features of malnutrition and its relationship with the CFTR genotype in a cystic fibrosis (CF) adult population. DESIGN: Cross-sectional study. SETTING: Department of Pulmonology, Cochin Hospital, Paris, France. SUBJECTS: 163 CF adults seen between 1997 and 1999. RESULTS: Mean age was 28.8 y. Mean body mass index (BMI) was 19.1 kg/m2. Malnutrition (BMI<18.5 kg/m2) was seen in 81 patients (49.7%). Its severity was associated with diagnosis of CF before the age of 18 y (P<0.01), FEV1 values below 30% (P<0.01), the yearly decline of FEV1 (P<0.01), pancreatic insufficiency (P<0.01) and gastro-oesophageal reflux (P<0.01). Malnutrition was observed in 58.7% of patients with a severe CFTR genotype but in 28.6% of patients with a mild genotype (P<0.001). CONCLUSION: Malnutrition remains frequent in adults with CF except in patients presenting with a mild CFTR genotype (leading to a mild phenotype and to later diagnosis).

Adult↗

Combined oral and enema treatment with Pentasa (mesalazine) is superior to oral therapy alone in patients with extensive mild/moderate active ulcerative colitis: a randomised, double blind, placebo controlled study.

BACKGROUND AND AIMS: Oral aminosalicylates are well established in the treatment of active mild/moderate ulcerative colitis (UC) when the disease is extensive (that is, beyond the splenic flexure). The majority of clinical symptoms relate to disease activity in the distal part of the colon and therefore this study was designed to investigate if adding a mesalazine enema to oral mesalazine has additional benefit for patients with extensive mild/moderate active UC. METHODS: A randomised double blind study was performed in 127 ambulatory patients. All received 4 g/day (twice daily dosing) oral mesalazine for eight weeks. During the initial four weeks, they additionally received an enema at bedtime containing 1 g of mesalazine or placebo. Disease activity was assessed using the ulcerative colitis disease activity index, with clinical and endoscopic signs at four and eight weeks. RESULTS: Remission was obtained in 44% (95% confidence interval (CI) 31%, 58%) of the mesalazine enema group (Me) and in 34% (95% CI 21%, 49%) of the placebo enema group (Pl) at four weeks (p = 0.31) and in 64% (95% CI 50%, 76%) of the Me group versus 43% (95% CI 28%, 58%) of the Pl group at eight weeks (p = 0.03). Improvement was obtained in 89% (95% CI 78%, 96%) of the Me group versus 62% (95% CI 46%, 75%) of the Pl group at four weeks (p = 0.0008) and in 86% (95% CI 75%, 94%) of the Me group versus 68% (95% CI 53%, 81%) of the Pl group at eight weeks (p = 0.026). CONCLUSION: In patients with extensive mild/moderate active UC, the combination therapy is superior to oral therapy. It is safe, well accepted, and may be regarded as firstline treatment.

Administration, Oral↗

Inflammatory bowel disease: what is new?

This article reviews a selection of 50 papers on inflammatory bowel disease published between April 2002 and August 2003. The new information and progress summarized here includes: the role of bacteria, their interaction with CARD15/NOD2 gene products and the modulating effects of probiotics; new imaging techniques, such as wireless capsule endoscopy and chromoendoscopy for detecting dysplasia, and fecal markers. It has not been possible to review every aspect of treatment, and the focus here is on factors capable of predicting the efficacy and tolerance of infliximab and new treatments, including natalizumab, thalidomide, cyclophosphamide and 6-thioguanine.

Antibodies, Monoclonal↗

Review article: gut flora and inflammatory bowel disease.

The pathogenesis of inflammatory bowel disease involves interactions between the host susceptibility, mucosal immunity and intestinal microflora. There is therefore great interest in the changes in the endogenous flora in inflammatory bowel disease patients and in the establishment of potential genetic variations in host responses to endogenous bacteria. In this review, we summarize the modifications in the various regional ecosystems in the gastrointestinal tract during inflammatory bowel disease (luminal bacteria in faeces or inside the gastrointestinal tract, bacteria in mucus and bacteria directly attached to the mucosa). Results were obtained following a 'candidate microorganism strategy' and, as is occurring increasingly frequently, following a 'full description strategy', which has progressed largely due to the development of culture-independent techniques. The possibility of modifying the ecosystem using prebiotics or probiotics offers hope for new treatment developments, particularly in the prevention of relapse.

Bacteria↗

Tioguanine in patients with Crohn's disease intolerant or resistant to azathioprine/mercaptopurine.

BACKGROUND: Tioguanine (TG) is an antimetabolite which may be regarded as an alternative to azathioprine (AZA)/mercaptopurine (MP) in patients with inflammatory bowel diseases. AIMS: : To evaluate the tolerance and efficacy of TG in patients with Crohn's disease, intolerant or resistant to AZA/MP. METHODS: An open prospective study was made on Crohn's disease patients treated with TG. Intolerance to AZA/MP was defined as a reaction occurring within 1 month after introduction of AZA/MP, including pancreatitis, abdominal pain, fever, arthralgia, myalgia, cutaneous rash, fatigue, alopecia, hepatitis and digestive intolerance. Resistance to AZA/MP was defined as the persistence of activity after at least 3 months of AZA/MP therapy. RESULTS: Forty-nine Crohn's disease patients (36 women, 13 men; intolerance: n = 39; resistance: n= 10) were treated with TG (20 mg/day). Clinical pancreatitis did not recur under TG. Five patients (10%) had to stop TG due to intolerant reactions observed 13-21 days after TG was started. No haematological side-effects were observed under TG. The probability of clinical remission without corticosteroids or infliximab at 6 and 12 months was 46% and 79%, respectively, in the 40 patients with active disease at baseline. The probability of clinical relapse during maintenance TG therapy at 6 and 12 months was 29% and 53%, respectively, in the 28 patients in remission at baseline or who had achieved remission on TG. CONCLUSIONS: TG is a possible alternative treatment in Crohn's disease patients, intolerant (especially for pancreatitis) or resistant to AZA/MP.

Adult↗

Infliximab for refractory ulcerative colitis or indeterminate colitis: an open-label multicentre study.

BACKGROUND: The efficacy of infliximab in ulcerative colitis (UC) and indeterminate colitis has been poorly assessed and preliminary results are conflicting. METHODS: The records of 30 patients treated with infliximab for ulcerative colitis (n=19) or indeterminate colitis (n=11) were reviewed. Infliximab was given because of steroid resistance (n=18), dependence (n=5) or intolerance (n=7); five patients had failed on cyclosporin; 19 patients had a severe flare-up. RESULTS: Median duration of follow-up was 10 months. In 28 patients with active disease, the response rate was 75% at day 7, with 43% having a complete remission, and 50% at month 1, with 32% having a complete remission. Among the 22 responders, the probability of relapse was 73% at month 6. The probability of complete remission without steroids, taking into account the re-treatment for relapse (n=11), was 57% (95% confidence interval (CI): 45% to 69%) at month 6. The probability of colectomy was 33% (95% CI: 23% to 43%) at month 12. In indeterminate colitis, response rate was only 50% at day 7 and 30% at month 1. Concomitant use of antimetabolite agents was associated with better results. CONCLUSIONS: Infliximab was able to induce a rapid response in some patients with UC or indeterminate colitis refractory to conventional treatment. Long-term results were less favourable, with frequent relapses, and about one-third of the patients required a colectomy.

Adolescent↗

Safety of probiotics that contain lactobacilli or bifidobacteria.

Lactobacilli and bifidobacteria are extremely rare causes of infection in humans, as are probiotics based on these organisms. This lack of pathogenicity extends across all age groups and to immunocompromised individuals. Strains used for new probiotics should be chosen from the commensal flora of humans and should not carry intrinsic resistance to antibiotics that would prevent treatment of a rare probiotic infection. Vigilance regarding the detection of possible rare cases of infection due to probiotics should be maintained, and isolates should be sent to reference centers for molecular characterization and confirmation.

Bifidobacteriales Infections↗

Alterations of the dominant faecal bacterial groups in patients with Crohn's disease of the colon.

BACKGROUND AND AIMS: The colonic microflora is involved in the pathogenesis of Crohn's disease (CD) but less than 30% of the microflora can be cultured. We investigated potential differences in the faecal microflora between patients with colonic CD in remission (n=9), patients with active colonic CD (n=8), and healthy volunteers (n=16) using culture independent techniques. METHODS: Quantitative dot blot hybridisation with six radiolabelled 16S ribosomal ribonucleic acid (rRNA) targeting oligonucleotide probes was used to measure the proportions of rRNA corresponding to each phylogenetic group. Temporal temperature gradient gel electrophoresis (TTGE) of 16S rDNA was used to evaluate dominant species diversity. RESULTS: Enterobacteria were significantly increased in active and quiescent CD. Probe additivity was significantly lower in patients (65 (11)% and 69 (6)% in active CD and quiescent CD) than in healthy controls (99 (7)%). TTGE profiles varied markedly between active and quiescent CD but were stable in healthy conditions. CONCLUSION: The biodiversity of the microflora remains high in patients with CD. Enterobacteria were observed significantly more frequently in CD than in health, and more than 30% of the dominant flora belonged to yet undefined phylogenetic groups.

Adolescent↗