Expression of Hyaluronidase-4 in a Rat Spinal Cord Hemisection Model

STUDY DESIGN: Examination of hyaluronidase-4 (Hyal-4) expression in a rat spinal cord hemisection model. PURPOSE: To determine the status of Hyal-4 expression after hemisection of the spinal cord, and the relationship between its expression and that of chondroitin sulfate proteoglycans (CSPGs). OVERVIEW OF LITERATURE: CSPGs are expressed at the site of spinal cord injury and inhibit axon regeneration. Administration of exogenous chrondroitinase ABC (ChABC), derived from bacteria, digested CSPGs and promoted axonal regrowth. Using a rat hemisection model, we have demonstrated peak CSPGs levels at by 3 weeks after injury but then decreased spontaneously. Could there be an endogenous enzyme similar to ChABC in the spinal cord? It has been suggested that Hyal-4 is involved in CSPG degradation. METHODS: A rat hemisection model was prepared and spinal cord frozen sections were prepared at 4 days and 1, 2, 3, 4, 5, and 6 weeks post-cordotomy and stained for CSPGs and Hyal-4 and subjected to Western blotting. RESULTS: CSPGs appeared at the injury site at 4 days after hemisection, reached a peak after 3 weeks, and then decreased. Hyal-4 was observed around the injury site from 4 days after cordotomy and increased until after 5-6 weeks. Double staining showed Hyal-4 around CSPGs. Western blotting identified a band corresponding to Hyal-4 from 4 days after hemisection. CONCLUSIONS: Hyal-4 was expressed in a rat hemisection model in areas surrounding CSPGs, and as its peak was delayed compared with that of CSPGs. These results suggest the involvement of Hyal-4 in the digestion of CSPGs.

Thyroid cancer spinal metastases: critical appreciation of the surgical strategy for spinal metastases in decision-making

"The Surgical Strategy for Spinal Metastases" has been developed to facilitate decision-making in patients with spinal metastases. The decision-making in patients with thyroid cancer spinal metastases. We have reviewed 14 consecutive patients operated for thyroid cancer spinal metastases in Department of Orthopedic Surgery, Kanazawa University, Japan. The strategy score, suggested line of treatment, and the indicated course were detected for all patients whether treated before or after development of the strategy score, suggested line of treatment, and the indicated course were detected for all patients whether treated before or after development of the strategy and compared to the line of treatment used and the actual course. Postoperative survival was detected and compared between different scores. Overall, these 14 patients received 25 operations. Total scores after strategy application were 2 [7 operations; 28%], 3 [11 operations 44%], 4 [2 operations, 8%] and 5 [5 operations, 20%. The post-operative survival for patients has scores 2,3,4 and 5 were 75.6 +/- 25.8, 32.6 +/- 27.8, 23 and 18.4 +/- 9.8 months respectively. Survival correlated with the score with correlation coefficient equals -0.68 [P = 0.005]. Survival with scores 2 and 3 [candidates of long-term local control] was 19.7 +/- 10.5 months. The difference was statistically significant [P = 0.04]. In conclusion, the "Surgical Strategy for Spinal Metastases" provided appropriate guidelines for treatment in the patients with thyroid cancer spinal metastases