Vitexin alleviates ER-stress-activated apoptosis and the related inflammation in chondrocytes and inhibits the degeneration of cartilage in rats.

Excessive extracellular matrix degradation and chondrocyte apoptosis are the pathological features of osteoarthritis (OA). The ability of flavonoid compounds isolated from Chinese hawthorn leaves to exert protective effects on several diseases, via inhibition of oxidative stress and inflammation, has been demonstrated in several studies. This study explored the effects of vitexin on chondrocytes, and the underlying mechanisms thereof. Vitexin, an active ingredient in hawthorn leaf extracts, was shown to exert protective effects on chondrocytes, by inhibiting the expression of GRP78 and PDI, and an apoptotic protein (CHOP) induced by interleukin-1ß. It also modulated thapsigargin-induced upregulation of GRP78 and PDI and subsequently an apoptotic protein (CHOP). Among rat chondrocytes, both the ER stress-activated nuclear factor kappa B (NF-κB) pathway and the induced expression of inflammatory cytokines (IL-6 and TNF-α) were significantly inhibited by vitexin. Finally, vitexin attenuated the progression of OA in vivo in rats. Taken together, all data demonstrate the relationship of ER stress and inflammation in the progression of OA, the ability of vitexin to protect chondrocytes and thus its therapeutic potential in patients with OA.

An ultrastructural study of chondroptosis: programmed cell death in degenerative intervertebral discs in vivo.

Apoptosis has been regarded to mediate intervertebral disc degeneration (IDD); however, the basic question of how the apoptotic bodies are cleared in the avascular intervertebral disc without phagocytes, which are essential to apoptosis, remains to be elucidated. Our goals were to investigate the ultrastructure of nucleus pulposus (NP) cells undergoing chondroptosis, a variant of apoptotic cell death, in a rabbit annular needle-puncture model of IDD. Experimental IDD was induced by puncturing discs with a 16-G needle in New Zealand rabbits. At 4 and 12 weeks after puncture, progressive degeneration was demonstrated by X-ray, magnetic resonance imaging and histological staining. TUNEL staining suggested a significant increase in the apoptosis index in the degenerated NP. However, the percentage of apoptotic cells with the classic ultrastructure morphology was much less than that with chondroptotic ultrastructure morphology under transmission electron microscopy (TEM). The chondroptotic cells from the early to late stage were visualized under TEM. In addition, the percentage of chondroptotic cells was significantly enhanced in the degenerated NP. Furthermore, 'paralyzed' cells were found in the herniated tissue. Western blotting revealed an increase in caspase3 expression in the degenerated NP. The expression of the Golgi protein (58K) was increased by the fourth week after puncture but decreased later. These findings indicate that chondroptosis is a major type of programmed cell death in the degenerated rabbit NP that may be related to the progressive development of IDD.

Pterostilbene inhibits inflammation and ROS production in chondrocytes by activating Nrf2 pathway.

Pterostilbene has been reported as a potential drug to inhibit oxidative stress and inflammation. However, the effect of pterostilbene on chondrocytes and osteoarthritis remains to be elucidated. We sought to investigate whether pterostilbene could protect chondrocytes from inflammation and ROS production through factor erythroid 2-related factor 2 (Nrf2) activation. The pterostilbene toxicity on chondrocytes collected from cartilages of Sprague-Dawley rats was assessed by CCK-8 test. Immunofluorescence and Western blotting explored the nuclear translocation of Nrf2. Nrf2 expression was silenced by siRNA to evaluate the involvement of Nrf2 in the effect of pterostilbene on chondrocytes. Finally, osteoarthritis model was established by the transection of anterior cruciate ligament and partial medial meniscectomy in rats, and then these rats received pterostilbene 30 mg/kg, daily, p.o. for 8 weeks. Histology and immunohistochemistry were used to assess histopathological change and Nrf2 expression in cartilage. Nuclear translocation of Nrf2 was stimulated by pterostilbene without cellular toxicity. Pterostilbene inhibited the level of COX-2, iNOS, PGE2, and NO, as well as the mitochondrial and total intracellular ROS production induced by IL-1ß in chondrocytes, partially reversed by the Nrf2 silencing. Pterostilbene prevented cartilage degeneration and promoted the nuclear translocation of Nrf2 in cartilage. These results suggest that pterostilbene could inhibit the IL-1ß-induced inflammation and ROS production in chondrocytes by stimulating the nuclear translocation of Nrf2.

Cortical bone trajectory screws for the middle-upper thorax: An anatomico-radiological study.

To quantify the reference data concerning the morphometrics of the middle-upper thorax to guide the placement of cortical bone trajectory (CBT) screws.Eighty patients were studied on computed tomography (CT) scans. The reference anatomical parameters were measured. Next, 20 cadaveric specimens were implanted with CBT screws based on CT measurements. These specimens were then judged directly from the cadaveric vertebrae and X-ray.The maximum length of the trajectory, the maximum diameter, and the cephaled angle exhibited a slight increase trend while the transverse and sagittal angles of the pedicle tended to decrease from T3 to T8. We recommend that the width of CBT screw for middle-upper thoracic spine is 5.0 mm, the length is 25 to 35 mm. The cadaveric anatomical study revealed that 5/240 screws penetrated in the medial or lateral areas, 5/240 screws penetrated in the superior or inferior pedicle wall, and 2/240 screws did not fit into the superior endplate of the pedicle.The CBT screws are safe for the middle-upper thorax. This study provides a theoretical basis for clinical surgery.

A mini-invasive technique for severe arthrofibrosis of the knee: A technical note.

PURPOSE: In this article, a mini-invasive technique is described, which consists of arthroscopic adhesiolysis and quadriceps pie-crusting lengthening basing on pre-operative sonographic examination. Sonographic diagnostic value of quadriceps tendon fibrosis is also evaluated. METHODS: Pre-operative sonographic examination was performed to make an accurate location diagnosis of quadriceps fibrosis. After arthroscopic adhesiolysis, percutaneous pie-crusting release was performed basing on preoperative sonographic examination. An 18-gauge needle was used to puncture the stiff fibrous band of the distal and lateral quadriceps tendon under maximum knee flexion. The contractural quadriceps tendon is gradually released after 60-100 needle punctures. RESULTS: This technique was performed in five post-traumatic stiff knees and three stiff knees after previous infection. The contractural rectus femoris tendon is average 22% thinner than contralateral parts according to sonographic measurement. Mean maximum flexion increased from 35° preoperatively to 80° after arthroscopic adhesiolysis and 120° after pie-crusting. CONCLUSIONS: This technique is a simple, effective and mini-invasive method, allowing an immediate, aggressive rehabilitation postoperatively. Pre-operative sonographic location of quadriceps tendon fibrosis could potentially improve the efficacy and accuracy of percutaneous pie-crusting procedures.

[Arthroscopic treatment of symptomatic anterior cruciate ligament cysts of the knee].

OBJECTIVE: To explore the clinical symptom and effect of arthroscopic treatment of symptomatic anterior cruciate ligament (ACL) cysts of the knee. METHODS: Clinical data from 12 symptomatic ACL cysts patients from January 2005 to December 2010 were retrospectively analyzed,including 8 males and 4 females,with an average age of (33.7±9.5) years old (ranged, 19 to 53 years old). The locations were the left knee in 5 cases and the right knee in 7 cases. The disease duration ranged from 3 to 48 months,with a mean of (15.8±13.2) months. All cysts were arthroscopically resected. Range of motion was measured preoperatively and postoperatively, and Lysholm scoring system was used to evaluate the knee function. RESULTS: All the incisions healed by first intention, and no complications occurred. Twelve patients were followed up for an average of (32.3±6.6) months(ranged, 24 to 48 months). The symptoms of arthralgia,swelling and interlocking of the affected knees disappeared. There was no recurrence during the follow-up. There were significant differences in the range of motion and Lysholm score between pre-operation and post-operation. CONCLUSION: Arthroscopic surgery, showing its advantages of minimal invasion and rapid recovery,is an effective measure in the treatment of ACL cysts.