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

Study DesignExamination of hyaluronidase-4 (Hyal-4) expression in a rat spinal cord hemisection model.PurposeTo 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 LiteratureCSPGs 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.MethodsA 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.ResultsCSPGs 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.ConclusionsHyal-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

四点支持器を用いた腹臥位手術における圧力と褥瘡発生との関係

金沢大学医薬保健研究域保健学系手術室では腹臥位手術の褥瘡発生率が高い. その原因として, 患者は四点支持器の上に腹臥位固定されるため, 四点支持器と身体との接触面積が小さく骨突出部にかかる圧力が高いのではないか, また時間経過とともに身体がずれて底づきすることにより, 骨突出部にかかる圧力が高くなるのではないかと考えた. この2つの仮説を検証する目的で, 腹臥位手術を受ける患者を対象に腹臥位固定中の四点支持器と右腸骨部皮膚との接触面の圧力を連続測定し, 褥瘡の有無別に比較した. その結果18名中14名に反応性充血, 4名にStage Iの褥瘡が発生した. Stage I発生者の最大体圧値は反応性充血発生者とくらべて有意に高値であった(P=.035). また, 両者で腹臥位固定開始時と終了時の平均体圧値, 最大体圧値には差がなかった. 腹臥位手術における褥瘡予防を図るための指標として腹臥位固定開始時の最大体圧値を用いることにより, 除圧ケアの介入が可能であることが示唆された.The incidence of pressure ulcers is high in prone position surgery. We hypothesized that the cause for this high incidence is as follows: (1) High pressure is placed on the bony areas of the body when the patient\u27s body is fixed on the Hall frame and the contact area between the body and the operating table is small. (2) The pressure increases for bottoming out to shear force with time on the bony areas of the body. In order to verify the above hypotheses, we examined adult patients who underwent prone position surgery. Specifically, we measured the real-time pressure placed on the contact area between the patients\u27 right ilium and the Hall frame and examined the presence of pressure ulcers. The results of the experiment showed that 14 out of 18 patients developed blanching erythema and 4 developed Stage I pressure ulcers. The development of Stage I pressure ulcers was found to be related to maximum interface pressure. Our study suggests that using the maximum interface pressure at the beginning of the prone position setting as an index for pressure reduction care may be effective in pressure ulcer prevention in prone position surgery.日本褥瘡学会の許可を得て登録_2021.9.2