by Hongtao Li, Li Xu, Longxin An, Xiaojing Li, Linjing Zhang, Jun Liu, Kaili Zhai, Xuecheng Sun, Naibo Feng
PurposeTo evaluate whether posterior column screws penetrate the posterior cortical surface of the acetabulum when assessed using obturator oblique radiographic imaging.
MethodsComputed tomography (CT) scans were performed on the right acetabulum of 50 healthy adults to measure the angle (α) between the posterior wall of the acetabulum and the sagittal plane at the level of the femoral head’s maximal diameter. In addition, five cadaveric pelvises were subjected to C-arm fluoroscopic imaging. A 6 cm long, 1.5 mm Kirschner wire was positioned along the posterior surface of the acetabular posterior column, aligned with the greater sciatic notch, and imaged in both the 45° and α-degree obturator oblique views. The radiographic line visualized from the Kirschner wire in the obturator oblique view was defined as the posterior iliac line, and its anatomical relationship with the posterior surface of the posterior column was analyzed. Subsequently, a 2.5 mm Kirschner wire was inserted into the posterior column at the standard entry point for screw placement using an electric drill, with the wire tip intentionally positioned between the posterior iliac line and the posterior rim in the 45° obturator oblique view. The trajectory of the wire was assessed under both 45° and α-degree obturator oblique views to determine its relation to the osseous corridor.
ResultsThe measured angle between the posterior surface of the acetabular posterior column and the sagittal plane was (60.2 ± 2.5)°. In the 45° obturator oblique view, the posterior iliac line corresponded with the outer edge of the iliac crest superiorly and the outer edge of the ischium inferiorly, while the posterior wall was projected posterior to the midpoint of the posterior iliac line. In the α° obturator oblique view, the posterior iliac line maintained this alignment but intersected centrally with the posterior acetabular wall. The 2.5 mm Kirschner wire remained within the osseous corridor under the 45° view but potentially extended beyond it under the α° view.
ConclusionWhen the posterior column screw is visualized posterior to the posterior iliac line in the 45° obturator oblique view, further assessment using a α° view is necessary. If the screw appears anterior to the posterior iliac line in the α° view, it indicates that the posterior cortical surface has not been breached.
by Xuecheng Sun, Bo Huang, Gaobo Ruan, Aie Xu
BackgroundVitiligo, a chronic autoimmune disease linked to excess oxidative stress, can be temporarily improved. Bone marrow mesenchymal stem cells (BMSCs)-derived exosomes (BMSCs-Exos) have recently emerged as a promising novel therapeutic means for vitiligo.
MethodsExosomes were isolated and characterized from BMSCs-conditioned medium. PIG3V cells and those transfected with NRF2 siRNA or negative control were cultured under normal conditions or exposure to hydrogen peroxide (H₂O₂) to induce oxidative stress, with addition of BMSCs-conditioned medium, conditioned medium from BMSCs pretreated with GW4869 (referred to as BMSCs-GW4869), or BMSCs-Exos. Cell viability, apoptosis, and oxidative stress parameters, including cellular glutathione (GSH)/oxidized glutathione (GSSG) ratio, superoxide dismutase (SOD), reactive oxygen species (ROS), and malondialdehyde (MDA), were assessed. The expression of Ki67, NRF2, HO1, BAC, and Bcl-2 was measured.
ResultsBMSC-Exos significantly enhanced cell viability and reduced apoptosis and oxidative stress in H₂O₂-treated PIG3V cells. Simultaneously, BMSCs-Exos reversed H₂O₂-induced downregulation of Ki67, NRF2, HO1, and Bcl-2, and upregulation of BAX in PIG3V cells. Silencing NRF2 by siRNA in PIG3V cells prior to H2O2 treatment abolished the protective effect of BMSCs-Exos and decreased the HO1 expression.
ConclusionsBMSCs-Exos protect melanocytes from vitiliog-related oxidative stress by mitigating oxidative damage through induction of NRF2/HO1 expression.