Reparative effects of chronic intermittent hypobaric hypoxia pre­treatment on intervertebral disc degeneration in rats.

Previous studies have indicated that chronic intermittent hypobaric hypoxia (CIHH) preconditioning can inhibit TNF­α and other related inflammatory cytokines and exerts protective effect on intervertebral disc degeneration disease (IDD) in rats; however, the mechanism is still unclear. The present study aimed to explore the repair mechanisms of CIHH on IDD in rats. In the experiment, 48 adult Sprague­Dawley rats were selected and randomly divided into an experimental group (CIHH­IDD), a degenerative group (IDD) and a control group (CON). The CIHH­IDD group of rats (n=16) were treated with CIHH (simulated 3000 m altitude, 5 h per day, 28 days; PO2=108.8 mmHg) before disc degeneration surgery. The IDD group of rats (n=16) underwent tail­vertebral intervertebral disc surgery to establish a model of intervertebral disc degeneration. The CON group of rats (n=16) did not receive any treatments. After surgery, the disc height index was calculated using X­ray analysis of rat tail vertebrae, the degeneration process was observed and repair was evaluated by chemically staining degenerative intervertebral disc tissue slices. The expression levels of basic fibroblast growth factor (bFGF), TGFß1, Collagen I and Collagen II were measured in the intervertebral disc tissue using western blotting; while the expression levels of bFGF, TGFß1 and hypoxia­inducible factor 1­α (HIF­1α) were measured in rat serum using ELISA. The results demonstrated that: i) The degree of intervertebral disc height degeneration in CIHH­IDD rats was significantly lower compared with that in IDD rats (P<0.05); ii) the expression levels of bFGF, TGFß1 and HIF­1α were higher in CIHH­IDD rat serum compared with those in IDD rat serum (P<0.05); iii) optical microscopy revealed that the degree of disc degeneration was relatively mild in CIHH­IDD rats; and iv) the protein expression levels of bFGF, TGFß1 and collagen II were increased in CIHH­IDD rat intervertebral disc tissues compared with those of IDD rats, while the overexpression of collagen I protein was inhibited. Overall, after CIHH pre­treatment, the expression levels of bFGF and TGFß1 were up­regulated, which play notable roles in repairing degenerative intervertebral discs in rats.

Effects of P-Coumarate 3-Hydroxylase Downregulation on the Compositional and Structural Characteristics of Lignin and Hemicelluloses in Poplar Wood (Populus alba × Populus glandulosa).

Elucidating the chemical and structural characteristics of hemicelluloses and lignin in the p-coumarate 3-hydroxylase (C3H) down-regulated poplar wood will be beneficial to the upstream gene validation and downstream biomass conversion of this kind of transgenic poplar. Herein, the representative hemicelluloses and lignin with unaltered structures were prepared from control (CK) and C3H down-regulated 84K poplars. Modern analytical techniques, such as 13C NMR, 2D-HSQC NMR, and gel chromatography (GPC), were performed to better delineate the structural changes of hemicelluloses and lignin caused by transgenesis. Results showed that both the hemicelluloses (H-CK and H-C3H) extracted from control and C3H down-regulated poplar wood have a chain backbone of (1→4)-ß-D-Xylan with 4-O-Me-α-D-GlcpA as side chain, and the branch degree of the H-C3H is higher than that of H-CK. With regarding to the lignin macromolecules, NMR results demonstrated that the syringyl/guaiacyl (S/G) ratio and dominant substructure ß-O-4 linkages in C3H down-regulated poplar were lower than those of control poplar wood. By contrast, native lignin from C3H down-regulated poplar wood exhibited higher contents of p-hydroxybenzoate (PB) and p-hydroxyphenyl (H) units. In short, C3H down-regulation resulted in the chemical and structural changes of the hemicelluloses and lignin in these poplar wood. The identified structures will facilitate the downstream utilization and applications of lignocellulosic materials in the biorefinery strategy. Furthermore, this study could provide some illuminating results for genetic breeding on the improvement of wood properties and efficient utilization of poplar wood.

Accurate Placement of Cannulated Screws in Femoral Neck Fractures: Screw and Guide Wire Combined Technique.

Cannulated screw fixation is widely used in the treatment of femoral neck fractures. During surgery, we often face the situation that a guide wire needs to be adjusted because of poor positioning in the femoral neck. It is difficult to adjust the direction of the guide wire in the neck of the femur due to its elasticity. This study developed a practical technique to adjust the guide wire to the correct position. When the direction of insertion of the guide wire has deviated, first, measure the length of the guide wire. Second, select the appropriate cannulated screw based on the measurement, and screw the cannulated screw in along the direction of the guide wire to Ward's triangle. Then return the guide wire to the front of the cannulated screw. At this time, the cannulated screw can be used as a built-in guide, and a screwdriver can be used to fine-tune the position of the screw to the optimal direction under the X-ray guidance. Finally, the cannulated screw is screwed in in this direction until it passes through the Ward triangle area, and the guide wire is inserted. This technique can help doctors insert a guide wire more quickly and accurately, reducing intraoperative injury and the operation time.

Treatment of posterolateral tibial plateau fractures with a rotational support plate and special pressurizer: technical note and retrospective case series.

BACKGROUND: In tibial plateau fractures, the posterolateral segment of the tibia plateau is frequently affected and challenging to treat. Although there are many surgical approaches and fixation methods for the treatment of these fractures, all of these methods have limitations. We designed a new rotational support plate (RSP) and a special pressurizer that can fix the fracture directly via the anterolateral approach. This method is advantageous because it leads to little trauma, involves a simple operation, and has a reliable fixation effect. This study details the technique of treating these fractures with the RSP and special pressurizer and provides the outcomes. METHODS: From May 2016 to January 2019, the data of 12 patients with posterolateral tibial plateau fractures treated with the RSP and special pressurizer in our hospital were retrospectively analyzed. Postoperative rehabilitation was advised, knee X-rays were taken at follow-ups, and fracture healing, complications, and knee range of motion were assessed. The Hospital for Special Surgery (HSS) knee score and Knee Injury and Osteoarthritis Outcome Score (KOOS) were used to evaluate knee function at the last follow-up. RESULTS: The average follow-up time of all patients was 16.5 months (range, 12-25 months). The average bony union time was 3.2 months (range, 3-4.5 months). At the last follow-up, the average knee range of motion was 138° (range, 107-145°). The average HSS score was 91 (range, 64-98). The average KOOS Symptoms score was 90 (range, 75-96). The average KOOS Pain score was 91 (range, 72-97). The average KOOS ADL score was 91 (range, 74-97). The average KOOS sport/recreation score was 83 (range, 70-90). The average KOOS QOL score was 88 (range, 69-93). Skin necrosis, incision infections, and fixation failure did not occur during the follow-up period. CONCLUSIONS: With our newly designed RSP and special pressurizer, posterolateral tibial plateau fractures can be easily and effectively reduced and fixed through the anterolateral approach, which serves as a novel treatment for posterolateral tibial plateau fractures.

Modified distally based sural nerve flaps in acute traumatic forefeet reconstructions.

Conventional reversed sural flaps have been used to cover lower one-third of the leg defects. However, the experience of the authors indicates that when the soft-tissue defect located at the dorsum of the metatarsophalangeal joint, distal marginal necrosis of the flaps usually occurs, which is the exact part of the flap that one needs the most. Finding a new method to augment the blood supply of the flap can be a difficult task. The authors found there is a constant cutaneous branch emanate from the peroneal artery at the point 11.0 +/- 1.7-cm upon the lateral malleolus. Ten modified distally based reverse sural artery flaps, in which the cutaneous branches from the peroneal artery 11.0 +/- 1.7-cm upon the lateral malleolus were added, were performed for the distal-third of the foot reconstruction between 2003 and 2006. All of the flaps survived completely after the operation. Distal marginal necrosis did not occur in any of the flaps. When conventional local flaps are inadequate, this flap should be considered for its reliability and low associated morbidity.