Edge-strand of BepA interacts with immature LptD on the ß-barrel assembly machine to direct it to on- and off-pathways.

The outer membrane (OM) of Gram-negative bacteria functions as a selective permeability barrier. Escherichia coli periplasmic Zn-metallopeptidase BepA contributes to the maintenance of OM integrity through its involvement in the biogenesis and degradation of LptD, a ß-barrel protein component of the lipopolysaccharide translocon. BepA either promotes the maturation of LptD when it is on the normal assembly pathway (on-pathway) or degrades it when its assembly is compromised (off-pathway). BepA performs these functions probably on the ß-barrel assembly machinery (BAM) complex. However, how BepA recognizes and directs an immature LptD to different pathways remains unclear. Here, we explored the interactions among BepA, LptD, and the BAM complex. We found that the interaction of the BepA edge-strand located adjacent to the active site with LptD was crucial not only for proteolysis but also, unexpectedly, for assembly promotion of LptD. Site-directed crosslinking analyses indicated that the unstructured N-terminal half of the ß-barrel-forming domain of an immature LptD contacts with the BepA edge-strand. Furthermore, the C-terminal region of the ß-barrel-forming domain of the BepA-bound LptD intermediate interacted with a 'seam' strand of BamA, suggesting that BepA recognized LptD assembling on the BAM complex. Our findings provide important insights into the functional mechanism of BepA.

Comparison of range of motion during movement from supine to sitting position in healthy young and elderly participants.

[Purpose] The purpose of this study was to compare the range of motion (ROM) during supine-to-sitting position (StSP) movement between healthy young and elderly participants to understand age-related tendencies, which is beneficial for the assessment and treatment of frail elderly. [Participants and Methods] The participants were 14 healthy young males (age, 19-24 years) and 16 healthy elderly individuals (8 males and 8 females; age, 65-74 years). Rising movement was performed 5 times freely at a comfortable speed. [Results] The joint angles during StSP movements in right shoulder abduction, extension of both shoulder joints, right elbow flexion, trunk extension, and adduction of both hip joints were significantly larger, whereas neck flexion, trunk flexion, and left hip joint abduction were significantly smaller in the healthy elderly participants than in the healthy young participants. All joint movements were earlier in the elderly participants than in the healthy young participants. [Conclusion] The results of this study suggest that focusing on how to use both upper limbs is important, in addition to the neck and trunk, when evaluating StSP movement. Similarly, to encourage independence during StSP movement, the elbow extensors must be strengthened.

Stabilizing transpelvic prosthetic socket for a patient with spinal cord injury sustaining right partial hemipelvectomy and left hip disarticulation.

A bucket-type transpelvic socket was fabricated for a man with paraplegia from spinal cord injury, who underwent right partial pelvic amputation and left hip disarticulation. His main problem was inability to sit due to asymmetrical pelvic shape. We prescribed a transpelvic prosthetic socket to enable him to sit again. The socket consisted of a dual structure: a hard frame and soft liner. The main features of the socket were redistribution of pressure to prevent recurrence of pressure ulcer, and a slightly backward tilt to maintain a comfortable sitting position. In addition, the socket had small air holes for ventilation; a big window in the abdominal area for management of stoma and cystostomy; and two straps for donning it independently. In addition, we confirmed the internal pressure distribution in the socket by a pressure mapping system to prevent reoccurrence of skin trouble. Finally, the patient regained independence in activities of daily living, including driving a car, after two months of rehabilitative training.