@article{AistleitnerHeinzHoermannetal.2013, author = {Aistleitner, Karin and Heinz, Christian and Hoermann, Alexandra and Heinz, Eva and Montanaro, Jacqueline and Schulz, Frederik and Maier, Elke and Pichler, Peter and Benz, Roland and Horn, Matthias}, title = {Identification and Characterization of a Novel Porin Family Highlights a Major Difference in the Outer Membrane of Chlamydial Symbionts and Pathogens}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {1}, doi = {10.1371/journal.pone.0055010}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-131176}, pages = {e55010}, year = {2013}, abstract = {The Chlamydiae constitute an evolutionary well separated group of intracellular bacteria comprising important pathogens of humans as well as symbionts of protozoa. The amoeba symbiont Protochlamydia amoebophila lacks a homologue of the most abundant outer membrane protein of the Chlamydiaceae, the major outer membrane protein MOMP, highlighting a major difference between environmental chlamydiae and their pathogenic counterparts. We recently identified a novel family of putative porins encoded in the genome of P. amoebophila by in silico analysis. Two of these Protochlamydia outer membrane proteins, PomS (pc1489) and PomT (pc1077), are highly abundant in outer membrane preparations of this organism. Here we show that all four members of this putative porin family are toxic when expressed in the heterologous host Escherichia coli. Immunofluorescence analysis using antibodies against heterologously expressed PomT and PomS purified directly from elementary bodies, respectively, demonstrated the location of both proteins in the outer membrane of P. amoebophila. The location of the most abundant protein PomS was further confirmed by immuno-transmission electron microscopy. We could show that pomS is transcribed, and the corresponding protein is present in the outer membrane throughout the complete developmental cycle, suggesting an essential role for P. amoebophila. Lipid bilayer measurements demonstrated that PomS functions as a porin with anion-selectivity and a pore size similar to the Chlamydiaceae MOMP. Taken together, our results suggest that PomS, possibly in concert with PomT and other members of this porin family, is the functional equivalent of MOMP in P. amoebophila. This work contributes to our understanding of the adaptations of symbiotic and pathogenic chlamydiae to their different eukaryotic hosts.}, language = {en} } @article{GreiserGreiserAhrensetal.2012, author = {Greiser, Eberhard M. and Greiser, Karin Halina and Ahrens, Wolfgang and Hagen, Rudolf and Lazszig, Roland and Maier, Heinz and Schick, Bernhard and Zenner, Hans Peter}, title = {Risk factors for nasal malignancies in German men: the South-German Nasal cancer study}, series = {BMC Cancer}, volume = {12}, journal = {BMC Cancer}, number = {506}, doi = {10.1186/1471-2407-12-506}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-133365}, year = {2012}, abstract = {Background: There are few studies of the effects of nasal snuff and environmental factors on the risk of nasal cancer. This study aimed to investigate the impact of using nasal snuff and of other risk factors on the risk of nasal cancer in German men. Methods: A population-based case-control study was conducted in the German Federal States of Bavaria and Baden-Wurttemberg. Tumor registries and ear, nose and throat departments provided access to patients born in 1926 or later. Results: Telephone interviews were conducted with 427 cases (mean age 62.1 years) and 2.401 population-based controls (mean age 60.8 years). Ever-use of nasal snuff was associated with an odds ratio (OR) for nasal cancer of 1.45 (95\% confidence interval [CI] 0.88-2.38) in the total study population, whereas OR in smokers was 2.01 (95\% CI 1.00-4.02) and in never smokers was 1.10 (95\% CI 0.43-2.80). The OR in ever-smokers vs. never-smokers was 1.60 (95\% CI 1.24-2.07), with an OR of 1.06 (95\% CI 1.05-1.07) per pack-year smoked, and the risk was significantly decreased after quitting smoking. Exposure to hardwood dust for at least 1 year resulted in an OR of 2.33 (95\% CI 1.40-3.91) in the total population, which was further increased in never-smokers (OR 4.89, 95\% CI 1.92-12.49) in analyses stratified by smoking status. The OR for nasal cancer after exposure to organic solvents for at least 1 year was 1.53 (1.17-2.01). Ever-use of nasal sprays/nasal lavage for at least 1 month rendered an OR of 1.59 (1.04-2.44). The OR after use of insecticides in homes was 1.48 (95\% CI 1.04-2.11). Conclusions: Smoking and exposure to hardwood dust were confirmed as risk factors for nasal carcinoma. There is evidence that exposure to organic solvents, and in-house use of insecticides could represent novel risk factors. Exposure to asbestos and use of nasal snuff were risk factors in smokers only.}, language = {en} }