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Helicobacter pylori causes disease in the human stomach and in mouse and gerbil stomach models. Previous results have shown that motility is critical for H. pylori to colonize mice, gerbils, and other animal models. The role of chemotaxis, however, in colonization and disease is less well understood. Two genes in the H. pylori chemotaxis pathway, cheY and tlpB, which encode the chemotaxis response regulator and a methyl-accepting chemoreceptor, respectively, were disrupted. The cheY mutation was complemented with a wild-type copy of cheY inserted into the chromosomal rdxA gene. The cheY mutant lost chemotaxis but retained motility, while all other strains were motile and chemotactic in vitro. These strains were inoculated into gerbils either alone or in combination with the wild-type strain, and colonization and inflammation were assessed. While the cheY mutant completely failed to colonize gerbil stomachs, the tlpB mutant colonized at levels similar to those of the wild type. With the tlpB mutant, there was a substantial decrease in inflammation in the gerbil stomach compared to that with the wild type. Furthermore, there were differences in the numbers of each immune cell in the tlpB-mutant-infected stomach: the ratio of lymphocytes to neutrophils was about 8 to 1 in the wild type but only about 1 to 1 in the mutant. These results suggest that the TlpB chemoreceptor plays an important role in the inflammatory response while the CheY chemotaxis regulator plays a critical role in initial colonization. Chemotaxis mutants may provide new insights into the steps involved in H. pylori pathogenesis.

The energy levels of triplet states of doubly charge oxygen, obtained using double charge transfer spectroscopy, have been examined in the light of ab initio calculations. Four peaks were found in the double charge transfer spectrum with energies of 41.1±0.2, 43.2±0.2, 48.2±0.3, and 51.3±0.3 eV, respectively. The first and third peaks have been assigned to the 3Σ+u and the 3Πu excited states, respectively. The second peak has been assigned to the population of the 3Πg states. The configuration of the state at 51.3 eV is unknown. The effect of the symmetry rule Σ+\Σ- is discussed and the validity of the spin conservation rule is demonstrated when a proton is used as a projectile in this experimental technique. [ABSTRACT FROM AUTHOR]

Forward head and shoulder postures and associated muscle imbalances are prevalent among today's workers, according to ongoing research in the physical therapy field. Information on proper posture should be used proactively to educate employees as part of injury prevention training. Maintaining muscle strength in the desirable posture will require ongoing exercise and attention from the worker. The self-direct approach will not eliminate all cases of tendonitis, epicondylitis and other disorders, but it will have a significant positive impact.