[CO2-laser-assisted de-epithelialization of perforation margins of persistent tympanic membrane perforations. An alternative to conventional surgical procedures]. / Die CO2-Laser-assistierte Perforationsanfrischung bei persistierender Trommelfellperforation. Eine Alternative zu konventionellen operativen Vorgehensweisen.

INTRODUCTION: The standard treatment of persistent eardrum perforation is conventional surgical closure using myringoplasty or a tympanoplasty type I. In this study the valence of a modified, CO(2)-laser-assisted de-epithelialization of perforation margins was investigated. MATERIAL AND METHODS: A total of 44 patients with mesotympanal eardrum perforation (diameter 1-5 mm) were included in a partially retrospective and partially prospective study. The genesis of the eardrum perforations was partially traumatic or the eardrum did not heal after spontaneous perforation caused by an acute otitis media or after surgery. The procedure was performed under topical anaesthesia. Focussed, adjacent, single CO(2) laser pulses (1 watt, 0.05 s) were applied with the laser otoscope Otoscan (Lumenis, Yokneam, Israel) along the edge of the perforation until complete de-epithelialization. This was done to stimulate growth. Closure of eardrum perforation was monitored using an ear microscope and if this treatment was not successful after three attempts conventional surgical therapy was suggested. RESULTS: Complete eardrum closure occurred in 27 cases (61%), 17 patients (39%) had a residual perforation, of which 9 experienced a significant reduction of the perforation. There were no complications during and after the treatment. CONCLUSION: A closure rate of at least 61% (27/44) can be expected with a CO(2)-laser-assisted de-epithelialization of the perforation margins. This procedure can be performed under topical anaesthesia and is an economic, painless and facile alternative to conventional surgical treatment.

Heterologous expression and characterization of choline oxidase from the soil bacterium Arthrobacter nicotianae.

In the course of a microbial screening of soil samples for new oxidases, different enrichment strategies were carried out. With choline as the only carbon source, a microorganism was isolated and identified as Arthrobacter nicotianae. From this strain, a gene coding for a choline oxidase was isolated from chromosomal DNA. This gene named codA was cloned in Escherichia coli BL21-Gold and the protein (An_CodA) heterologously overexpressed as a soluble intracellular protein of 59.1 kDa. Basic biochemical characterization of purified protein revealed a pH optimum of 7.4 and activity over a broad temperature range (15-70 degrees C). Specific activities were determined toward choline chloride (4.70 +/- 0.12 U/mg) and the synthetic analogs bis(2-hydroxyethyl)-dimethylammonium chloride (0.05 +/- 0.45 x 10(-2) U/mg) and tris-(2-hydroxyethyl)-methylammonium methylsulfate (0.01 +/- 0.12 x 10(-2) U/mg). With increasing number of oxidizable groups, a significant decrease in activity was noted. Determination of kinetic parameters in atmorspheric oxygen resulted in K (M) = 1.51 +/- 0.09 mM and V (max) = 42.73 +/- 0.42 mU/min for choline chloride and K (M) = 4.77 +/- 0.76 mM and V (max) = 48.40 +/- 2.88 mU/min for the reaction intermediate betaine aldehyde respectively. Nuclear magnetic resonance spectroscopic analysis of the products formed during the enzyme reaction with choline chloride showed that in vitro the intermediate betaine aldehyde exists also free in solution.

[Biomorphology of the Bacterial Invasion in Chronic pharyngotonsillitis ]. / Biomorphologie der Infektionsherde in rezidivierenden Mandelentzündungen.

BACKGROUND: The study investigates whether relapses of chronicpharyngotonsillitis result from new infections caused by theoro-pharyngeal microbial flora or are reactivations of persistent bacterial infections of the tonsils. METHODS: 90 patients, who were surgically treated for chronicpharyngotonsillitis (age 13 months to 38 years, at least 5 episodes of disease and antibiotic treatment in the past) were included. The surgery was performed in the antibiotic- and symptom-free period (at least 6 weeks after the last exacerbation). Sections of tonsillar tissue were investigated for invasive bacteria using fluorescence in situ hybridization (FISH) with group and species-specific 15/23S RNA based probes. RESULTS: Abundant foci of invasive bacteria were found in 86% of the resected tonsils, despite previous treatment with antibiotica and absent symptoms of ongoing infection. The diffuse infiltration of the tonsils was most predominant in the youger children. Local invasive processes such as abscesses, fissures filled with pus and superficial infiltration of the tonsillar epithelium were more typical for adults. All of the foci were polymicrobial and contained up to 10 different species or groups of bacteria. The local concentrations of invasive bacteria were up to 1012 bacteria/ml. CONCLUSIONS: The chronic pharyngotonsillitis is the result of persistent invasive bacterial infections. The polymicrobial nature of the infectious foci enables them to resist the antibiotic treatment and to exacerbate afterwards. The surgical treatment is unavoidable as long as antibiotic treatment fails to clear the infection.

Spatial organisation of microbiota in quiescent adenoiditis and tonsillitis.

BACKGROUND: The reasons for recurrent adenotonsillitis are poorly understood. METHODS: The in situ composition of microbiota of nasal (5 children, 25 adults) and of hypertrophied adenoid and tonsillar tissue (50 children, 20 adults) was investigated using a broad range of fluorescent oligonucleotide probes targeted to bacterial rRNA. None of the patients had clinical signs of infection at the time of surgery. RESULTS: Multiple foci of ongoing purulent infections were found within hypertrophied adenoid and tonsillar tissue in 83% of patients, including islands and lawns of bacteria adherent to the epithelium, with concomitant marked inflammatory response, fissures filled with bacteria and pus, and diffuse infiltration of the tonsils by bacteria, microabscesses, and macrophages containing phagocytosed microorganisms. Haemophilusinfluenzae mainly diffusely infiltrated the tissue, Streptococcus and Bacteroides were typically found in fissures, and Fusobacteria,Pseudomonas and Burkholderia were exclusively located within adherent bacterial layers and infiltrates. The microbiota were always polymicrobial. CONCLUSIONS: Purulent processes persist during asymptomatic periods of adenotonsillitis. Most bacteria involved in this process are covered by a thick inflammatory infiltrate, are deeply invading, or are located within macrophages. The distribution of the bacteria within tonsils may be responsible for the failure of antibiotic treatment.