Effects of Radiation on Spinal Dura Mater and Surrounding Tissue in Mice

13301甲第4336号博士（医学）金沢大学博士論文本文Full 以下に掲載：PLOS ONE 10(7) pp.e0133806 2015. Public Library of Science. 共著者：Noriaki Yokogawa, Hideki Murakami, Satoru Demura, Satoshi Kato, Katsuhito Yoshioka, Miyuki Yamamoto, Shoichi Iseki, Hiroyuki Tsuchiy

Study on differentiation factors for main disease identification of intermittent claudication

Intermittent Claudication [1] is a walking symptom. After a short time walking, patients suffer from pains at lower limbs. But if taking a rest, the pains can be relieved and they can walk again. Unfortunately, it arises from not one but mainly two kinds of diseases: LSS (lumber spinal canal stenosis) and PAD (peripheral arterial disease). Additionally, it is reported that symptom is similar and LSS groups is furthermore divided into two main groups: L4 and L5 groups. Therefore, it is clinically very important to differentiate which diseases the patients suffer from, PAD, L4 or L5. We aims at developing the system to differentiate them from short walking motion data. In our previous paper [2], we derived differentiation factors, but did not consider the difference between L4 and L5 and the results are limited. This paper focuses on biarticular muscles associated with the diseases, and derive new and effective differentiation factors. The results supports their effectiveness and validity. © 2012 IEEE

Walking motion analysis of intermittent claudication and its application to medical diagnosis

There are mainly two kinds of diseases in intermittent claudication. One is lumbar spinal canal stenosis (LSS) and the other is peripheral arterial disease (PAD). Differentiating LSS and PAD is a critical issue. Wrong differentiation might cause amputation of lower extremities. At small clinics and hospitals, simple and cheap differentiation system is required. Concerning this, this paper investigated walking motions of the patients. The subject with LED markers walked on the treadmill until she or he felt pain. We recorded the walking motion by camera and tracked the LED markers. Treadmill enables to measure walking motion for a long time in a small space, and LED marker provides position of every joint in the walking. Then, we can get the information such as joint angle trajectory, hemi-foot step, stance and swing phases without any other sensors like foot switch or force plate. We compared walking motions of healthy persons, LSS patients and PAD patients, found their features and 3 factors for disease differentiation; average bending angle of knee joint at the start of stance phase, average dorsiflexion angle of ankle joint, and average hemi-foot step length. The results indicate that 2 dimensional images of walking motion for several seconds are enough for deriving the factors. Then, we can construct the simple examination system for the disease differentiation. © 2010 IEEE

Effects of radiation on spinal dura mater and surrounding tissue in mice

Purpose Spinal surgery in a previously irradiated field carries increased risk of perioperative complications, such as delayed wound healing or wound infection. In addition, adhesion around the dura mater is often observed clinically. Therefore, similar to radiation-induced fibrosis- a major late-stage radiation injury in other tissue-epidural fibrosis is anticipated to occur after spinal radiation. In this study, we performed histopathologic assessment of postirradiation changes in the spinal dura mater and peridural tissue in mice. Materials and Methods The thoracolumbar transition of ddY mice was irradiated with a single dose of 10 or 20 Gy. After resection of the irradiated spine, occurrence of epidural fibrosis and expression of transforming growth factor beta 1 in the spinal dura mater were evaluated. In addition, microstructures in the spinal dura mater and peridural tissue were assessed using an electron microscope. Results In the 20-Gy irradiated mice, epidural fibrosis first occurred around 12 weeks postirradiation, and was observed in all cases from 16 weeks postirradiation. In contrast, epidural fibrosis was not observed in the nonirradiated mice. Compared with the nonirradiated mice, the 10- and 20-Gy irradiated mice had significantly more overexpression of transforming growth factor beta 1 at 1 week postirradiation and in the late stages after irradiation. In microstructural assessment, the arachnoid barrier cell layer was thinned at 12 and 24 weeks postirradiation compared with that in the nonirradiated mice. Conclusion In mice, spinal epidural fibrosis develops in the late stages after high-dose irradiation, and overexpression of transforming growth factor beta 1 occurs in a manner similar to that seen in radiation-induced fibrosis in other tissue. Additionally, thinning of the arachnoid barrier cell layer was observed in the late stages after irradiation. Thus, consideration should be given to the possibility that these phenomena can occur as radiation-induced injuries of the spine. Copyright © 2015 Yokogawa et al

Repeated total en bloc spondylectomy for spinal metastases at different sites in one patient

Purpose: Total en bloc spondylectomy (TES) is accompanied by preoperative embolization of segmental arteries, which is limited to three consecutive levels to avoid the risk of spinal cord ischemia. We retrospectively examined the efficacy and safety of repeated TES with embolization of more than three levels of segmental arteries. Methods: Seven patients underwent TES twice for spinal metastases at different levels. Every patient underwent embolization of the bilateral segmental arteries before each surgery. We assessed the total number of segmental arteries embolized, the existence of Adamkiewicz arteries during the embolization procedure, intraoperative blood loss, and the motor function of the lower limbs, using the American Spinal Injury Association (ASIA) motor score. Results: No patient experienced any motor deficit after embolization. During the embolization procedure, an Adamkiewicz artery was depicted in five patients, which precluded embolization at that level. The median number of segmental arteries embolized in total was 9 (9–11). Intraoperative blood loss (median, IQR) was 480 (420–630) ml during the first surgery and 520 (280–600) ml during the second surgery. The ASIA motor scores (median, IQR) were as follows; 100 (98–100) (first admission), 100 (100–100) (first discharge), 100 (98–100) (second admission), and 97 (94–100) (second discharge). No patients had developed statistically significant neurological deterioration, and there had been no local recurrence after a median follow-up of 17.8 months (range 1–51 months). Conclusion: Repeated TES procedures can be performed safely even if more than three levels of segmental arteries are embolized. © 2015, Springer-Verlag Berlin Heidelberg.Embargo Period 12 month

Motor function of the upper-extremity after transection of the second thoracic nerve root during total en bloc spondylectomy

Background: In total en bloc spondylectomy (TES) of upper thoracic spine including the second thoracic (T2) vertebra, T2 nerve roots are usually transected. In this study, we examined the association between transection of the T2 nerve roots and upper-extremity motor function in patients with upper thoracic TES. Copyright:Methods: We assessed 16 patients who underwent upper thoracic TES with bilateral transection of the T2 nerve roots. Patients were divided into three groups: 3 patients without any processing of T1 and upper nerve roots (T2 group), 7 with extensive dissection of T1 nerve roots (T1-2 group), and 6 with extensive dissection of T1 and upper nerve roots (C-T2 group). Postoperative upper-extremity motor function was compared between the groups.Results: Postoperative deterioration of upper-extremity motor function was observed in 9 of the 16 patients (56.3%). Three of the 7 patients in the T1-2 group and all 6 patients in the C-T2 group showed deterioration of upper-extremity motor function, but there was no deterioration in the T2 group. In the T1-2 group, 3 patients showed mild deterioration that did not affect their activities of daily living and they achieved complete recovery at the latest follow-up examination. In contrast, severe dysfunction occurred frequently in the C-T2 group, without recovery at the latest follow-up.Conclusions: The transection of the T2 nerve roots alone did not result in upper-extremity motor dysfunction; rather, the dysfunction is caused by the extensive dissection of the T1 and upper nerve roots. Therefore, transection of the T2 nerve roots in upper thoracic TES seems to be an acceptable procedure with satisfactory outcomes

Implantation of Liquid Nitrogen Frozen Tumor Tissue after Posterior Decompression and Stabilization for Metastatic Spinal Tumors

Study DesignA retrospective study.PurposeTo evaluate the immunity-enhancing effect of implantation of a liquid nitrogen-treated tumor.Overview of LiteratureWe have developed a new technique of implanting a tumor frozen in liquid nitrogen after posterior decompression and stabilization, with the aim of enhancing antitumor immunity in order to prolong the survival period of the patient. In the current study, the immunity-enhancing effect of this new technique has been evaluated.MethodsThe subjects were 19 patients in whom we had earlier performed decompression and stabilization between April 2011 and September 2013. The 19 subjects were divided into two groups, namely a frozen autologous tumor tissue implantation group (n=15; "implantation group"), which consisted of patients, who underwent implantation with autologous tumor tissue frozen in liquid nitrogen, and a control group (n=4), which consisted of patients, who did not undergo autologous cancer transplantation. To evaluate the immunity-enhancing effect of the protocol, plasma cytokines (interferon [IFN]-γ and interleukin [IL]-12) were analyzed before surgery and a month after surgery.ResultsThe mean rate of increase in IFN-γ was significantly higher in the implantation group (p=0.03). Regarding IL-12, no significant difference was observed between the groups, although the implantation group exhibited increased levels of IL-12 (p=0.22).ConclusionsDecompression and stabilization combined with autologous frozen tumor cell implantation can enhance cancer immunity in metastatic spinal tumor patients. It is hypothesized that this procedure might prevent local recurrence and prolong survival period

Surgical site infection after total en bloc spondylectomy: Risk factors and the preventive new technology

Background context Surgical site infection (SSI) associated with instruments remains a serious and common complication in patients who undergo total en bloc spondylectomy (TES). It is very important that the risk factors for SSI are known to prevent it.Purpose The purpose of the study was to identify independent risk factors for SSI after TES and evaluate the positive effect of iodine-supported spinal instruments in the prevention of SSI after TES.Study design This is a retrospective clinical study.Patient sample One hundred twenty-five patients who underwent TES for vertebral tumor were evaluated.Outcome measures Incidence rate of SSI, risk factors for SSI after TES, and safety of iodine-supported spinal instruments were the outcome measures.Methods Risk factors for SSI were analyzed using logistic regression. In recent 69 patients with iodine-supported spinal instruments, the thyroid hormone levels in the blood were examined to confirm if iodine from the implant influenced thyroid function. Postoperative radiological evaluations were performed regularly.Results The rate of SSI was 6.4% (8/125 patients). By multivariate logistic regression, combined anterior and posterior approach and nonuse of iodine-supported spinal instruments were associated with an increased risk of SSI. The rate of SSI without iodine-supported spinal instruments was 12.5%, whereas the rate with iodine-supported spinal instruments was 1.4%. This difference was statistically significant. There were no detected abnormalities of thyroid gland function with the use of iodine-supported instruments. Among the 69 patients with iodine-supported spinal instruments, 2 patients required additional surgery because of instrument failure. However, there were no obvious involvements with the use of iodine-supported spinal instruments.Conclusions This study identified combined anterior and posterior approach and nonuse of iodine-supported spinal instruments to be independent risk factors for SSI after TES. Iodine-supported spinal instrument was extremely effective for prevention of SSI in patients with compromised status, and it had no detection of cytotoxic or adverse effects on the patients

A histological examination of spinal reconstruction using a frozen bone autograft

金沢大学医薬保健研究域医学系Our aim was to compare the process of bone formation after reconstruction of the vertebral body using a titanium cage with either a liquid nitrogen-treated (frozen) bone autograft or non-treated fresh bone autograft. Twelve canine beagles underwent anterior reconstruction of the 5th lumbar vertebrae using a titanium cage and bone autograft. Bone formation was compared across four experimental groups: fresh bone autograft groups, with animals sacrificed at either 8 or 16 weeks post-reconstruction, and liquid nitrogen-treated (frozen) bone autograft groups, with animals again sacrificed at either 8 or 16 weeks post-reconstruction. Bone formation was evaluated histologically by calculating the proportion of \u27reaction\u27 and \u27mature bone\u27 regions at the ends of the cage, its center, and ventral/dorsal sides. The reaction region contained osteocytes with a nucleus and osteoblasts accumulated on the surface of an osteoid, while a laminar structure was visible for mature bone regions. For fresh bone autografts, the reaction and mature bone regions significantly increased from 8 to 16 weeks post-reconstruction. By comparison, for frozen autografts, the reaction bone region did not significantly increase from 8 to 16 weeks post-reconstruction, while the mature bone region did increase over this time period. The proportion of reaction bone was higher at the ends and dorsal side of the cage at 8 weeks, for both graft types, with greater bone formation at the center of the cage at 16 weeks only for the fresh bone autograft. Therefore, bone formation in the anterior spinal reconstruction site tended to be delayed when using a frozen bone autograft compared to a fresh bone autograft. The bone formation process, however, was similar for both groups, beginning at the ends and dorsal side of the cage adjacent to the surrounding vertebral bone. © 2018 Shinmura et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Superconductivity and physical properties of Ba24Si100 determined from electric transport, specific-heat capacity, and magnetic susceptibility measurements

Both Ba24Si100 and Ba24Ge100 with crystallographically identical structure are found to be superconducting at 1.4 and 0.27 K, respectively. Physical properties of this superconductor Ba24Si100 are studied by electric transport, specific heat capacity, and magnetic susceptibility measurements. The density of states at the Fermi level NEF=0.148 states eV-1(Siatom)-1 and a distinct jump of Cp at the superconducting transition temperature ΔCp=0.272JK-1mol-1 are obtained. An exponential fit of Cp below the superconducting states gives an energy gap 2Δ=0.423meV and shows that this is a superconductor having s-wave character or isotropic energy gap. On the basis of our experimental data other important physical parameters are also derived