Roger Willén

The Effect of Exogenous Administration of Lactobacillus reuteri R2LC and Oat Fiber on Acetic Acid-Induced Colitis in the Rat

The potential beneficial effect of exogenous administration of Lactobacillus on acetic acid-induced colitis was evaluated in the rat. Colitis was induced by instillation of 4% acetic acid for 15 sec in an exteriorized colonic segment. This produced uniform colitis with a threefold increase in myeloperoxidase (MPO) activity of the colonic tissue (an index of neutrophil infiltration) and a sixfold increase in plasma exudation into the lumen of the colon (mucosal permeability) as evaluated 4 days after acetic acid administration. Intracolonic administration of L. reuteri R2LC immediately after acetic acid administration, at a dose of 5 ml of 7 x 10(7) colony-forming units (CFU)/ml in two forms: either as pure bacterial suspension or as fermented oatmeal soup, prevented the development of colitis. Thus, the morphologic score, MPO activity, and mucosal permeability were almost normalized by Lactobacillus treatment. Initiating the treatment 24 h after acetic acid administration or using lower doses of 1 ml for 3 consecutive days resulted in a smaller protective effect. We conclude that exogenous administration of L. reuteri R2LC prevents the development of acetic acid-induced colitis in the rat.

Vestibular Nerve Fiber Proliferation in Vulvar Vestibulitis Syndrome

Objective To evaluate nerve fiber density in vestibular specimens from women operated upon for vulvar vestibulitis. Methods Forty-seven women with vulvar vestibulitis syndrome underwent modified posterior vestibulectomies. Vestibular specimens were analyzed after being stained for S-100 neural tissue protein. Women were followed up for 2 years. Results In specimens from 44 of 47 patients, the densities and numbers of nerve fibers per square unit in the preparations were greater than those in specimens from six control women. In the patients, a statistically significant linear correlation was found between inflammation and nerve bundle density in the preparations (Spearman rank correlation coefficient rs = .41; P = .005). There were no signs of infectious etiology in any preparation. No or slight postoperative dyspareunia was reported by 38 of 42 women after 6 months, 36 of 39 after 12 months, and 26 of 28 after 24 months. Conclusion Vestibular neural hyperplasia may provide a morphologic explanation of the pain in vulvar vestibulitis syndrome.

Impairment of Bacterial Flora in Human Ulcerative Colitis and Experimental Colitis in the Rat

Changes in the colonic mucosa-associated microflora were determined both in patients with active and inactive ulcerative colitis and in rats with acetic acid-induced colitis. In patients with active ulcerative colitis, significant decreases in the number of anaerobic bacteria (Brain Heart Infusion medium), anaerobic gram-negatives and Lactobacillus were found, whereas no changes were seen in the number of aerobic bacteria and Enterobacteriaceae. In patients with inactive ulcerative colitis, no significant differences in colonic mucosa-associated microflora could be demonstrated. Similar changes were seen in rats with acetic acid-induced colitis. Thus, 4 days after acetic acid administration, at which time the colitis was well developed as evaluated by morphological appearance and myeloperoxidase activity, reduction in the number of anaerobic bacteria and Lactobacillus was seen. The first day after acetic acid administration, when the colitis had not developed, or after 14 days, when the colitis had been overcome, no alterations were seen in the mucosa-associated microflora as compared with control rats. We conclude that a reduction in the number of anaerobic bacteria and Lactobacillus is a common feature in active colitis regardless of the origin of colitis.

Treatment of H. pylori infected mice with antioxidant astaxanthin reduces gastric inflammation, bacterial load and modulates cytokine release by splenocytes.

Helicobacter pylori is a gram-negative bacterium affecting about half of the world population, causing chronic gastritis type B dominated by activated phagocytes. In some patients the disease evolves into gastric ulcer, duodenal ulcer, gastric cancer or MALT lymphoma. The pathogenesis is in part caused by the immunological response. In mouse models and in human disease, the mucosal immune response is characterized by activated phagocytes. Mucosal T-lymphocytes are producing IFN-gamma thus increasing mucosal inflammation and mucosal damage. A low dietary intake of antioxidants such as carotenoids and vitamin C may be an important factor for acquisition of H. pylori by humans. Dietary antioxidants may also affect both acquisition of the infection and the bacterial load of H. pylori infected mice. Antioxidants, including carotenoids, have anti-inflammatory effects. The aim of the present study was to investigate whether dietary antoxidant induced modulation of H. pylori in mice affected the cytokines produced by H. pylori specific T-cells. We found that treatment of H. pylori infected mice with an algal cell extract containing the antioxidant astaxanthin reduces bacterial load and gastric inflammation. These changes are associated with a shift of the T-lymphocyte response from a predominant Th1-response dominated by IFN-gamma to a Th1/Th2-response with IFN-gamma and IL-4. To our knowledge, a switch from a Th1-response to a mixed Th1/Th2-response during an ongoing infection has not been reported previously.

Astaxanthin-rich algal meal and vitamin C inhibit Helicobacter pylori infection in BALB/cA mice

ABSTRACT Helicobacter pylori infection in humans is associated with chronic type B gastritis, peptic ulcer disease, and gastric carcinoma. A high intake of carotenoids and vitamin C has been proposed to prevent development of gastric malignancies. The aim of this study was to explore if the microalga Haematococcus pluvialisrich in the carotenoid astaxanthin and vitamin C can inhibit experimental H. pylori infection in a BALB/cA mouse model. Six-week-old BALB/cA mice were infected with the mouse-passagedH. pylori strain 119/95. At 2 weeks postinoculation mice were treated orally once daily for 10 days (i) with different doses of algal meal rich in astaxanthin (0.4, 2, and 4 g/kg of body weight, with the astaxanthin content at 10, 50, and 100 mg/kg, respectively), (ii) with a control meal (algal meal without astaxanthin, 4 g/kg), or (iii) with vitamin C (400 mg/kg). Five mice from each group were sacrificed 1 day after the cessation of treatment, and the other five animals were sacrificed 10 days after the cessation of treatment. Culture of H. pylori and determination of the inflammation score of the gastric mucosae were used to determine the outcome of the treatment. Mice treated with astaxanthin-rich algal meal or vitamin C showed significantly lower colonization levels and lower inflammation scores than those of untreated or control-meal-treated animals at 1 day and 10 days after the cessation of treatment. Lipid peroxidation was significantly decreased in mice treated with the astaxanthin-rich algal meal and vitamin C compared with that of animals not treated or treated with the control meal. Both astaxanthin-rich algal meal and vitamin C showed an inhibitory effect on H. pylori growth in vitro. In conclusion, antioxidants may be a new strategy for treating H. pylori infection in humans.

The role of bile and bile acids in bacterial translocation in obstructive jaundice in rats.

Male Sprague-Dawley rats were randomly divided into five groups in which group 1 received a sham operation (controls), groups 2-5 underwent common bile duct ligation and transection 14 days before the experiments. Two days prior to the studies, animals in groups 1 and 2 received saline orally, while groups 3-5 received an oral administration of either cholic acid, deoxycholic acid or whole bile. Specimens were taken for bacterial culture, and blood was collected for endotoxin assay. The rate of positive bacterial cultures from mesenteric lymph nodes in jaundiced saline-treated animals was significantly higher (p < 0.05) as compared with both controls and the other jaundiced animals treated with either bile or bile acids. Assays were positive for endotoxin in the jaundiced saline-treated group, whereas they were negative in both controls and bile- or bile-acid-treated animals. We conclude that oral administration of cholic acid, deoxycholic acid or whole bile inhibited bacterial translocation and endotoxin absorption in obstructive jaundice in the rat.

Inhibition of Helicobacter pylori infection by bovine milk glycoconjugates in a BAlb/cA mouse model.

The attachment of Helicobacter pylori to the human gastric mucosa is a complex process involving several specific structures recognised by the cell surface receptors. Sialylated multivalent high mol. wt glycoproteins have been shown to inhibit H. pylori sialic acid-specific haemagglutination. This study explored whether sialylated glycoconjugates from bovine milk could inhibit an experimental H. pylori infection in a mouse model. BALB/cA mice (6-8 weeks old) were inoculated with a mouse-passaged H. pylori strain 317p. Four weeks after infection the mice were given lactoferrin (iron-free LF or 20% iron-saturated LF) or bovine milk fat globule membrane fractions (MFGM or defatted MFGM) orally (400 mg/kg body weight) once daily for 10 days and then killed to examine for bacterial colonisation and gastritis. Mice treated with iron-free LF, 20% iron-saturated LF, MFGM or defatted MFGM showed 30%, 10%, 20% or 20% healing rates, respectively, when compared with the H. pylori-infected control. Gastric colonisation by H. pylori was remarkably decreased in all mice treated with bovine milk glycoconjugates and the inflammation score was also significantly lower in treated mice than in infected control animals. The fact that there was no significant difference between iron-free LF and iron-saturated LF or MFGM and defatted MFGM suggested that iron is not crucial for inhibition of H. pylori by lactoferrin and that the lipid part of MFGM is not important for anti-H. pylori activity. In conclusion, bovine milk glycoconjugates showed potencies to inhibit H. pylori infection in this mouse model and, therefore, could be considered as candidates for non-antibiotic strategies against H. pylori infection in man.

Barrett Esophagus: Risk Factors for Progression to Dysplasia and Adenocarcinoma

Objective:To evaluate risk factors for dysplasia and adenocarcinoma development in nondysplastic Barrett mucosa. Summary Background Data:The risk for patients with Barrett esophagus to develop esophageal adenocarcinoma is low, and most patients undergoing surveillance will not develop malignancy. Identification of risk factors may allow for more rational surveillance programs in which patients are stratified according to their individual risk of progressing to dysplasia and invasive adenocarcinoma. Methods:The development of dysplasia and esophageal adenocarcinoma was studied during long-term endoscopic and histologic surveillance in 140 patients with Barrett esophagus free from dysplasia. Risk factors for progression to dysplasia and adenocarcinoma were evaluated. Results:Median follow-up was 5.8 years. Forty-four patients (31.4%) developed low-grade dysplasia and 7 patients (5%) developed high-grade dysplasia or esophageal adenocarcinoma. Dysplasia development was significantly less common after antireflux surgery compared with conventional medical therapy. Low-grade dysplasia (relative risk = 5.5; 95% confidence interval, 1.1–28.6) and long duration of reflux symptoms (relative risk = 1.3; 95% confidence interval, 1.2–1.7) were independently associated with an increased risk of developing high-grade dysplasia or esophageal adenocarcinoma. Conclusions:Successful antireflux surgery protects the Barrett mucosa from developing high-grade dysplasia and esophageal adenocarcinoma, possibly by better control of reflux of gastric contents. Low-grade dysplasia is the only clinically useful risk factor that permits stratification of the surveillance intervals according to the risk of the individual patient.

Detection of adenocarcinoma in Barrett's oesophagus by means of laser induced fluorescence.

PATIENTS: Seven patients with Barretts metaplastic epithelium and oesophageal adenocarcinoma were investigated by means of laser induced fluorescence after low dose intravenous injection (0.35 mg/kg bw) of Photofrin (QLT, Vancouver, Canada). Laser induced fluorescence measurements were performed immediately after resection of the oesophagus. METHODS: Laser induced fluorescence spectra were recorded from 15-30 locations in each surgical specimen from normal mucosa, Barretts epithelium, and tumour tissue. Histological examination was performed on each location to correlate the fluorescence spectral characteristics with histological status of the epithelium (normal, metaplastic or malignant). Measurements were also performed during endoscopy in five patients to test the applicability of the method in a clinical setting. Fluorescence spectra were recorded and evaluated at characteristic wavelengths, and biopsy specimens were collected. Fluorescence ratios were calculated as the quotient of Photofrin fluorescence divided by autofluorescence. RESULTS: The mean (SD) fluorescence ratio values were 0.10 (0.058) for normal oesophageal mucosa, 0.16 (0.073) for normal gastric mucosa, 0.205 (0.17) for Barretts epithelium with moderate dysplasia, 0.79 (0.54) for severe dysplasia, and 0.78 (0.56) for adenocarcinoma. The highest fluorescence ratios were obtained for adenocarcinoma tissue, which could generally be distinguished from all nonmalignant tissue. Metaplastic Barretts epithelium also yielded higher fluorescence ratios than did normal mucosa. CONCLUSIONS: The results suggest that the technique can be used during endoscopy for real time tissue characterisation in the oesophagus, as an aid in detecting malignant transformation not macroscopically apparent at endoscopy.

The risk of dysplasia and cancer in the ileal pouch mucosa after restorative proctocolectomy for ulcerative proctocolitis is low: a long-term term follow-up study.

Aim  Some of the rare complications reported in patients with an ileopouch anal anastomosis (IPAA) after coloectomy for chronic ulcerative colitis are dysplasia and carcinoma. The supposed pathway is for the ileal pouch mucosa to go through adaptational changes then is to progress through the phases of chronic pouchitis, dysplasia and subsequently to adenocarcinoma. In many of these studies however, the dysplasia – cancer sequence is inconclusive since the carcinoma might have developed from the ileal mucosa itself or from residual viable rectal mucosa left behind. The purpose of this study was therefore to study the long‐term ileal mucosal adaptation patterns and the incidence and grading of dysplasia in the ileal pouch mucosa in patients previously operated on for ulcerative proctocolitis.