OmpA-like protein influences cell shape and adhesive activity of Tannerella forsythia

Tannerella forsythia, a gram-negative fusiform rod, is implicated in several types of oral anaerobic infections. Most gram-negative bacteria have OmpA-like proteins that are homologous to the OmpA protein in Escherichia coli. We identified an OmpA-like protein in T. forsythia encoded by the tf1331 gene as one of the major proteins by mass spectrometric analysis. Two-dimensional, diagonal electrophoresis showed that the OmpA-like protein formed a dimeric or trimeric structure via intermolecular disulfide bonds. A biotin labeling experiment revealed that a portion of the protein was exposed on the cell surface, even though T. forsythia possesses an S-layer at the outermost cell surface. Using a tf1331-deletion mutant, we showed that the OmpA-like protein affected cell morphology. The length of the mutant cell was reduced almost by half. Cell swelling was observed in more than 40% of the mutant cells. Moreover, the mutant exhibited decreased adhesion to fibronectin, retarded autoaggregation, and reduced cell surface hydrophobicity. These results suggest that the OmpA-like protein in T. forsythia plays an important role in cellular integrity and adhesive function.     

Discontinuation of leisure time impact-loading exercise is related to reduction of a calcaneus quantitative ultrasound parameter in young adult Japanese females: a 3-year follow-up study

Summary

A 3-year follow-up study on 334 young Japanese females enrolled in a university at the age of 18 years revealed that discontinuation of leisure time impact-loading exercises performed in junior high and/or high school was associated with increased risk of reduction in calcaneus osteo-sono assessment index (OSI).

Introduction

Bone strength rapidly increases during puberty and reaches its peak by the end of adolescence. The aim of this study was to determine the lifestyle factors that influence the maintenance of calcaneus OSI in young adult females around the time when peak bone mass is attained.

Methods

Annual health checkups including OSI measurements, anthropometrics, lifestyle analysis, and blood examination were performed 4 times on 334 Japanese females enrolled in a university at the age of 18 years. According to the slope of OSI change during the 3-year follow-up, the subjects were grouped into two categories: OSI loss (the lowest tertile) and OSI gain/stable (the second and third tertiles).

Results

At the baseline assessment, the OSI loss group had higher OSI and height and an earlier menarche age than the OSI gain/stable group. Performing leisure time impact-loading exercise in junior high and/or high school but discontinuing it at university was associated with increased risk of OSI loss, independent of OSI, height and weight at the age of 18 years, weight change during follow-up, age of menarche, energy-adjusted nutrient intake, and alcohol drinking; the odds ratios were 4.1–4.9 compared with those performing impact-loading exercise at university. In particular, duration, frequency, and subjective intensity of impact-loading exercise during high school were positively associated with OSI loss.

Conclusion

Discontinuation of leisure time impact-loading exercises performed during late adolescence is associated with an increased risk of OSI loss in young adult females during the 3-year follow-up period.     

Immune Evasion of Hepatoma Cancer Stem-Like Cells from Natural Killer Cells

Annals of Surgical Oncology - Poor prognosis in liver cancer is due to its high frequency of intrahepatic metastasis. Cancer stem-like cells (CSLCs), which possess the properties of stemness, tumor...     

Angiotensin I-converting enzyme gene polymorphism in two ethnic groups living in Brazil's southern region: association with age

BACKGROUND: Several studies have been published on the association between ACE (angiotensin I-converting enzyme) polymorphism and longevity. However, the results are controversial. METHODS: We analyzed the association between ACE polymorphism and age in two different ethnic populations: a population originating from different European countries (Gaucha Population, GP) and a population originating from Japan (JP). Both populations live in Brazil's southern region. RESULTS: We determined the ACE genotype in 834 persons aged 10-104 years. The ACE genotype and allele frequencies differed between the two populations, with the D allele being more frequent in GP than JP. We found an association between the DD genotype and D allele and age in the GP group only. The ACE polymorphism-age association occurred at age >60 years in the GP population with decreasing II frequency. CONCLUSION: We cannot dismiss the possibility of the association between ACE polymorphism and age involving linkage disequilibrium, since the nature of this phenomenon is still controversial. From our studies, it appears that there is a correlation between age, ethnicity, and ACE polymorphism. More of such studies are warranted, as further investigation in this area will have a high clinical relevance to cardiovascular disease and aging research.