Luteoloside protects the vascular endothelium against iron overload injury via the ROS/ADMA/DDAH II/eNOS/NO pathway.

Iron overload injury is considered to be a part of blood stasis syndrome of arthralgia in traditional Chinese medicine. Its primary therapies include clearing heat and detoxification, activating blood circulation, and removing blood stasis. Lonicera japonica flos (LJF) has long been known as an excellent antipyretic and antidote. Luteoloside (Lut) is one of the main components of LJF and exhibits antioxidant, anti-inflammatory, and cytoprotective properties. However, the protection of Lut against iron overload injury and its underlying mechanisms remain unclear. Therefore, HUVECs were exposed to 50 µmol·L-1 iron dextran for 48 h to establish an iron overload damage model and the effects of Lut were assessed. Our results showed that 20 µmol·L-1 Lut not only increased cell viability and weakened LDH activity, but also significantly up-regulated DDAHⅡ expression and activity, increased p-eNOS/eNOS ratio and NO content, and reduced ADMA content in HUVECs exposed to iron overload. Furthermore, Lut significantly attenuated intracellular/mitochondrial ROS generation, improved SOD, CAT, and GSH-Px activities, reduced MDA content, maintained MMP, inhibited mPTP opening, prevented cyt c from mitochondria released into cytoplasm, reduced cleaved-caspase3 expression, and ultimately decreased cell apoptosis induced by iron overload. The effects of Lut were similar to those of L-arginine (an ADMA competitive substrate), cyclosporin A (a mPTP blocker agent), and edaravone (a free radical scavenger) as positive controls. However, addition of pAD/DDAH II-shRNA adenovirus reversed the above beneficial effects of Lut. In conclusion, Lut can protect HUVECs against iron overload injury via the ROS/ADMA/DDAH II/eNOS/NO pathway. The mitochondria are the target organelles of Lut's protective effects.

Feasibility of anterior pedicle screw fixation in lumbosacral spine: a radiographic and cadaveric study.

BACKGROUND: The anterior pedicle screw (APS) technique for L5 and S1 is crucial for proper anterior lumbar interbody fusion (ALIF). This study aimed to determine the projection, screw trajectory angle, and bone screw passageway length (BSPL), as well as the screw insertion regularity and the operating area within which it is safe to perform insertion. METHODS: Forty patients with low back pain, all of whom had lumbar computed tomography scans available, was included in this retrospective analysis. Radiographic parameters were measured, including: the distances from the projection to the upper endplate, lower endplate, and midline; the transverse and sagittal screw angles; and the BSPL. In addition, 10 fresh adult cadaveric lumbosacral spine segments were selected to determine the safe anatomic area in which to operate. Finally, APSs were inserted in L5 and S1 to determine the regularity of APS insertion. RESULTS: We measured the anterior projection parameters, including: the distances to the upper endplate (L5: 12.5±1.3 mm; S1: 4.54±0.87 mm), lower endplate (L5: 17.3±1.6 mm), and midline (L5: 6.6±0.7 mm; S1: 6.6±0.6 mm); the screw trajectory angle, including the transverse screw angle (L5: 25.3±2.8°; S1: 25.7±2.6°), sagittal screw angle (L5: 17.1±1.7°; S1: 22.4±1.1°); and the BSPL (L5: 48.6±3.5 mm; S1: 48.0±3.5 mm). The regularity of APS insertion in L5 and S1 was determined. Upon the needle reaching a point in the lateral view, it reached the corresponding point in the anteroposterior (AP) view. The anatomic parameters of the safe operating area were as follows: the distance from the abdominal aortic bifurcation to the L5 lower edge (40.50±9.40 mm); the distance from the common iliac vein confluence to the L5 lower edge (27.80±8.60 mm); and the horizontal distance from the inner edge of the common iliac vein to the L5 lower edge (37.50±1.30 mm). We also determined the distance between S1 holes (29.30±1.30 mm), the L5/S1 intervertebral height (17.20±1.50 mm), and the safe operating area (2,058.20±84.30 mm2). CONCLUSIONS: This study has determined the projection, screw trajectory angle, and BSPL of APSs in L5 and S1, their insertion regularity, and the area in which the operation can be safely performed.

Appropriate insertion point for percutaneous pedicle screw placement in the lumbar spine using c-arm fluoroscopy: a cadaveric study.

BACKGROUND: We studied the characteristics and regularity of appropriate insertion points for percutaneous pedicle screw placement in the lumbar spine using C-arm X-ray fluoroscopy. The purpose of this study was to improve the accuracy of percutaneous pedicle screw placement and reduce the incidence of superior-level facet joint violation. METHODS: Six normal spinal specimens were included. Three different methods for placing percutaneous pedicle screws in the lumbar spine were applied, including the Roy-Camille method, Magerl method and Weinstein method. The relationships among the insertion point, pedicle projection and proximal facet joint on C-arm X-ray films were studied. The projection morphology of the vertebral pedicle in different segments of the lumbar spine was observed. The relationship between the outer edge of the pedicle projection and the outer edge of the cranial articular process was also studied. The distance between the insertion point and the facet joint (M1), the distance between the insertion point and outer edge of the cranial articular process (M2), and the distance between the insertion point and the projection center of the pedicle (M) were measured. RESULTS: In this study, we found that the projection shape of the vertebral pedicle differed across segments of the lumbar spine: the shape for L1-L3 was oval, and that for L4-L5 was round. The radiographic study showed that the outer edge of the cranial articular process was located on the lateral side of the outer edge of the pedicle projection and did not overlap with the pedicle projection. M for the Weinstein group was larger than that for the Roy-Camille group (P <  0.05). M1 for the Weinstein group was larger than that for the Roy-Camille and Magerl groups (P <  0.05). M2 for the Roy-Camille group was negative, M2 for the Magerl group was 0, and M2 for the Weinstein group was positive. CONCLUSION: Under C-arm X-ray fluoroscopy, we were able to accurately identify the characteristics and regularity of the appropriate insertion point for percutaneous pedicle screw placement in the lumbar spine, which was important for improving the accuracy of percutaneous pedicle screw placement and reducing the incidence of superior-level facet joint violation.