Elastography of nerves in the wrists of cyclists.

Purpose: This study aimed to investigate changes in the elasticity of the median and ulnar nerves in cyclists. Material and methods: The study included 30 cyclists and 2 non-biking reference groups that included 32 healthy volunteers and 32 individuals with ulnar nerve entrapment neuropathies. All participants underwent physical, ultrasonographic, and elastographic examinations including assessment of nerve cross-sectional area (CSA) and stiffness (SWE). The cyclists' group was tested before and after a 2-hour workout. Results: The values of ulnar nerve CSA and stiffness in Guyon's canal in resting cyclists were 5.30 ± 1.51 mm2 and 49.05 ± 11.18 kPa, respectively. These values were significantly higher than in the healthy volunteers, but not higher than in the nerve entrapment group. Median nerve CSA and stiffness at rest were 9.10 ± 2.61 mm2 and 38.54 ± 14.87 kPa, respectively. Both values were higher than respective values in the healthy group. Cycling induced an increase in all these parameters, although the increase in nerve stiffness was more noticeable than in CSA. Conclusions: The elasticity of the median and ulnar nerve in cyclists remains within normal limits, questioning the belief that cyclists are at risk of nerve palsy in Guyon's canal. However, cycling workout does exert compression, resulting in transient oedema of both nerves. The dynamics of changes was more noticeable in SWE examination than in conventional ultrasound, which may depend on SWE sensitivity.

Spinal Involvement in Patients with Chronic Non-Bacterial Osteomyelitis (CNO): An Analysis of Distinctive Imaging Features.

Spinal involvement by chronic non-bacterial osteomyelitis (CNO) has been increasingly reported in recent years, often being presented as a diagnostic dilemma requiring differential diagnosis with bacterial spondylodiscitis and/or neoplasia. This study was aimed at identifying the imaging features of CNO facilitating its differentiation from other spinal diseases. Two radiologists assessed the imaging studies of 45 patients (16 male and 29 female, aged from 6 to 75 years, 15 children) with CNO collected from 5 referential centers. Spinal lesions were found in 17 patients (2 children and 15 adults), most often in the thoracic spine. In children, the lesions involved short segments with a destruction of vertebral bodies. In adults, the main findings were prominent bone marrow edema and osteosclerosis, endplate irregularities, and ankylosing lesions extending over long segments; paraspinal inflammation was mild and abscesses were not observed. In both children and adults, the involvement of posterior elements (costovertebral and facet joints) emerged as an important discriminator between CNO and neoplasia/other inflammatory conditions. In conclusion, a careful inspection of imaging studies may help to reduce the number of biopsies performed in the diagnostic process of CNO.

Inversion of Correia repeat enclosed elements in Neisseria gonorrhoeae.

Neisseria gonorrhoeae is capable of causing gonorrhoea and more complex diseases in the human host. Within the gonococcal genome are over 100 copies of the insertion sequence-like Correia repeat enclosed element (CREE), which has been predicted to be mobile within the neisserial genomes. Although there is evidence of ancestral movement of these elements, no previous study has provided evidence for current mobilization. CREE has the ability to alter gene expression and regulation in many ways: by insertional mutagenesis, by introducing promoter elements, by generating mRNA processing sites and by association with non-coding RNAs. Previous studies have compared the genomic locations of CREEs in the Neisseria spp., demonstrating that otherwise identical regions have either the element or the target TA insertion site. In this study, we report for the first time, to our knowledge, movement of CREEs, through inversion of the element at its chromosomal location. Analysis of Ion Torrent generated genome sequence data from N. gonorrhoeae strain NCCP11945 passaged for 8 weeks in the laboratory under standard conditions and stress conditions revealed a total of 37 inversions: 24 were exclusively seen in the stressed sample, 7 were seen in the control sample and the remaining 3 were seen in both samples. These inversions have the capability to alter gene expression in N. gonorrhoeae through the previously determined activities of the sequence features of these elements, potentially resulting in reversible phase-variable gene expression.

Phase variable DNA repeats in Neisseria gonorrhoeae influence transcription, translation, and protein sequence variation.

There are many types of repeated DNA sequences in the genomes of the species of the genus Neisseria, from homopolymeric tracts to tandem repeats of hundreds of bases. Some of these have roles in the phase-variable expression of genes. When a repeat mediates phase variation, reversible switching between tract lengths occurs, which in the species of the genus Neisseria most often causes the gene to switch between on and off states through frame shifting of the open reading frame. Changes in repeat tract lengths may also influence the strength of transcription from a promoter. For phenotypes that can be readily observed, such as expression of the surface-expressed Opa proteins or pili, verification that repeats are mediating phase variation is relatively straightforward. For other genes, particularly those where the function has not been identified, gathering evidence of repeat tract changes can be more difficult. Here we present analysis of the repetitive sequences that could mediate phase variation in the Neisseria gonorrhoeae strain NCCP11945 genome sequence and compare these results with other gonococcal genome sequences. Evidence is presented for an updated phase-variable gene repertoire in this species, including a class of phase variation that causes amino acid changes at the C-terminus of the protein, not previously described in N. gonorrhoeae.