Augmented sensory biofeedback (BF) for postural control is widely used to improve postural stability. However, the effective sensory information in BF systems of motor learning for postural control is still unknown. The purpose of this study was to investigate the learning effects of visual versus auditory BF training in dynamic postural control. Eighteen healthy young adults were randomly divided into two groups (visual BF and auditory BF). In test sessions, participants were asked to bring the real-time center of pressure (COP) in line with a hidden target by body sway in the sagittal plane. The target moved in seven cycles of sine curves at 0.23Hz in the vertical direction on a monitor. In training sessions, the visual and auditory BF groups were required to change the magnitude of a visual circle and a sound, respectively, according to the distance between the COP and target in order to reach the target. The perceptual magnitudes of visual and auditory BF were equalized according to Stevens' power law. At the retention test, the auditory but not visual BF group demonstrated decreased postural performance errors in both the spatial and temporal parameters under the no-feedback condition. These findings suggest that visual BF increases the dependence on visual information to control postural performance, while auditory BF may enhance the integration of the proprioceptive sensory system, which contributes to motor learning without BF. These results suggest that auditory BF training improves motor learning of dynamic postural control.

Rationale: In some cases, autopsy is the first opportunity to find a previously unrecognized critical infection. Pathogens are identified by various methods, such as microscopic examination, special stains, culture tests, and immunohistochemistry. Here, we report a case of 16S ribosomal RNA (rRNA) gene sequencing using a postmortem formalin-fixed, paraffin-embedded (FFPE) tissue, which was useful for identifying pathogenic microbes. Patient concerns: Autopsy was performed on an 87-year-old man who had chronic renal failure and had developed sepsis from a central venous catheter infection 10 days before his death. Prior to these events, von Meyenburg complexes (VMCs) were also found during regular checkups. Diagnosis: Postmortem microscopic examination revealed acute purulent cholangitis with numerous microabscesses, accompanied by VMCs. Gram-negative rods were observed in some microabscesses, which were considered causative pathogens. Interventions: 16S rRNA gene sequencing using postmortem FFPE tissue Outcomes: Pseudomonas aeruginosa was identified, different from the one detected in the central venous catheter culture while alive. Lessons: 16S rRNA gene sequencing is a useful tool for identifying pathogenic microbes in postmortem FFPE tissues. This technique may be useful for amplicon sizes of approximately 100 bp or less.

The purpose of this study was to clarify the short-term effects of a repetitive cross-over step training for postural stability and postural strategies during one-leg standing. [Subjects and Methods] Fourteen healthy young adults participated in this study. In the test sessions before and after training, subjects maintained one-leg standing for up to 15 sec. In the training session, each subject repeatedly practiced the cross-over step in 100 trials. The distance from the center of pressure (COP) to the body's center of mass (COM) (COP-COM distance), and the body weight distribution and COP change mechanisms were evaluated to determine the effects of the practice. [Results] The results showed that the COP-COM distance during one-leg standing had shortened, together with increase of the body weight distribution mechanism in the acceleration phase and of COP-change mechanism in the deceleration phase after the practice. [Conclusion] Repetitive cross-over stepping changes postural strategies, improving postural stability during one-leg standing by reducing the COP-COM distance.