Helicobacter pylori

Klin Khir. 2010 May;(5):15-7.

Application of low-intensive laser irradiation in the treatment of perforative gastroduodenal ulcers.

[Article in Russian]

Makhmudov MG.

Abstract

Comparative analysis of results of surgical treatment, performed for perforative gastroduodenal ulcers in the patients, lacking H. pylori (control group) and owing this etiologic factor (main group), was conducted. Together with other conventional schemes of medicinal treatment in the early postoperative period a low-intensive irradiation of He-Ne laser was applied. Complete eradication of H. pylori was noted in 95.8% patients of the main group. In a late follow-up period (in 1-5 yrs observation terms) the frequency of recurrence, hemorrhage, pyloroduodenal stenosis and other surgical complications, occurring in the main group, was lesser than in a control one.

Eksp Klin Gastroenterol. 2010;(2):32-6.

The laser chromoendoscopy eradication of Helicobacter pylori

[Article in Russian]

Pavlov ON, Aleksandrov IuK.

Abstract

35 patients with absence of positive dynamics after course of treatment of diseases associated with Helicobacter pylori infection and without achievement of eradication are surveyed. The original technique of Helicobacter pylori endoscopy eradication with use of the therapeutic laser in length of a wave of 660 nanometers is offered. Carrying out of rate laser chromoendoscopy eradication considerably reduces terms of healing of inflammatory-destructive changes of stomach and duodenum mucous membrane allows achieving of Helicobacter pylori eradication.

Antimicrob Agents Chemother. 2005 Jul;49(7):2822-7.

Helicobacter pylori accumulates photoactive porphyrins and is killed by visible light.

Hamblin MR, Viveiros J, Yang C, Ahmadi A, Ganz RA, Tolkoff MJ.

Wellman Center for Photomedicine, Massachusetts General Hospital, 40 Blossom Street, BAR314B, Boston, Massachusetts 02114-2698, USA. hamblin@helix.mgh.harvard.edu

Abstract

Helicobacter pylori colonizes the mucus layer of the human stomach and duodenum, causes chronic gastritis, gastric ulcer, and is a risk factor for gastric adenocarcinoma. There is a 20% failure rate in antibiotic therapy, which is increasingly due to antibiotic resistance and necessitates the search for alternative antimicrobial methods. We have discovered that H. pylori when cultured in liquid medium, accumulates significant quantities of coproporphyrin and protoporphyrin IX, both in the cells and secreted into the medium. These photoactive porphyrins lead to cell death (up to 5 logs) by photodynamic action upon illumination with low doses of visible light, with blue/violet light being most efficient. The degree of killing increases with the age of the culture and is greater than that found with Propionibacterium acnes (another bacterium known to be photosensitive due to porphyrin accumulation). Both virulent and drug-resistant strains are killed. The data suggest that phototherapy might be used to treat H. pylori infection in the human stomach.

Med Microbiol. 1996 Apr;44(4):245-52.

The killing of Helicobacter pylori by low-power laser light in the presence of a photosensitiser.

Millson CE, Wilson M, Macrobert AJ, Bedwell J, Bown SG.

The National Medical Laser Centre, University College London Medical School, UK.

Abstract

Helicobacter pylori is associated with various gastrointestinal disorders. Lethal photosensitisation was investigated as a possible technique for killing H. pylori which might offer a better alternative to antibiotics. The susceptibility of H. pylori to lethal photosensitisation was determined by mixing suspensions of H. pylori with various photosensitisers and plating out on blood agar before irradiation with low-power laser light. Five sensitisers were studied further by mixing them with H. pylori in a tissue-culture plate and counting survivors after irradiation as a function of laser exposure time, dye concentration and pre-irradiation time. Crystal violet and thionine were ineffective as sensitisers, but zones of inhibition appeared with methylene blue (MB), protoporphyrin IX (PPIX), haematoporphyrin derivative (HPD), toluidine blue O (TBO) and disulphonated aluminium phthalocyanine (S2). Laser light or sensitiser alone did not affect bacterial viability. S2 (100 microg/ml) with a laser light energy density of 16 J/cm2, HPD (10O microg/ml) with 160 J/cm2, MB (100 microg/ml) with 21 J/cm2, PPIX (150 microg/ml) with 320 J/cm2 and TBO (50 microg/ml) with 160 J/cm2 all reduced bacterial viability by >99%. The killing of sensitised H. pylori by laser light offers a new approach to the treatment of localised infections when all colonised areas are accessible to light.

J Photochem Photobiol B. 1996 Jan;32(1-2):59-65.

Ex-vivo treatment of gastric Helicobacter infection by photodynamic therapy.

Millson CE, Wilson M, MacRobert AJ, Bown SG.

National Medical Laser Centre, University College London Medical School, UK.

Abstract

Attempts to develop PDT for eradication of Helicobacter infection have only been successful in vitro. We have investigated the effect of topical sensitization (except ALA) of Helicobacter mustelae on explanted ferret gastric mucosa using one of five sensitizers (methylene blue (MB), toluidine blue O (TBO), phthalocyanine, haematoporphyrin derivative and 5-aminolavulinic acid), followed by irradiation with an appropriately tuned copper vapour pumped dye laser. A 90% reduction in counts of bacteria sensitized with 0.75 mg TBO kg-1 were seen after irradiation with 200 J cm-2. Concentrations of MB of 0.75 mg kg-1 and 7.5 mg kg-1 were not toxic to H. mustelae, but the further addition of 20 J cm-2 laser light reduced colony counts by more than 99%. MB at a concentration of 75 mg kg-1 exhibited significant dark toxicity towards H. mustelae, but further addition of 20 J cm-2 laser light resulted in near eradication of all colonies. The remaining three compounds were ineffective. Finally, we studied the microscopic fluorescence distribution of MB (7.5 mg kg-1) on ferret gastric mucosa after topical administration. Fluorescence was greatest in the superficial mucosal layer, upon which lies the bacteria. However, from experiments on rats, the energy required to kill the sensitized bacteria was insufficient to damage the underlying mucosa. We conclude that Helicobacter can be killed on host mucosal epithelium following topical administration of MB and subsequent exposure to laser light.

Eksp Klin Gastroenterol. 2004;(4):29-32, 108.

State of humoral immunity and phagocytic activity in neutrophils in patients with ulcer and effect of low-intensity laser therapy.

[Article in Russian]

Burduli NM, Gutnova SK.

Abstract

The aim of our investigation was to study the influence of low-intensity laser therapy at the immunologic parameters and Helicobacter pylori (HP) microbial contamination in patients with exacerbation of peptic and duodenal ulcer. 100 patients aged 18-65 were examined and divided into 2 groups. The experimental group (75 patients) underwent a complex drug and laser therapy of various therapeutic techniques. The control group (25 patients) underwent only drug therapy. The results of this study show the immunocorrective effect of different methods of low-intensity laser therapy in the exacerbation period and more essential decrease of HP microbial contamination in the experimental group.