Biomechanical and Anatomical Validity of the Short Posterior Arch Screw

Jun Mizutani,Nozomu Inoue,Yoshihisa Otsuka,Aiharu Furuya,Alejandro A. Espinoza Orias,Takanobu Otsuka 대한척추신경외과학회 2019 Neurospine Vol.16 No.2

Objective: This study was conducted to clarify the validity of the short posterior arch screw (S-PAS). The S-PAS is inserted only in the pedicle-analogue portion of the posterior arch. The S-PAS screw length is almost half that conventional C1 lateral mass screws inserted via the posterior arch (via-PAS). S-PAS reduces the risk of vertebral artery injury (VAI) because it never reaches the transverse foramen. Although the biomechanical validity of various C1 lateral mass screws (C1LMS) analyzed in young specimens have been published, that of unicortically inserted C1LMS such as the unicortical Harms screw, S-PAS, and via-PAS for elderly patients is concerning because of the high prevalence of osteoporosis in the elderly. Methods: Nine fresh frozen cadavers (average age at death, 72.1 years) were used for pullout testing. The bone mineral density of each specimen was evaluated using quantitative computed tomography. Results: The pullout strength of via-PAS (1,048.5 N) was significantly greater than that of the unicortical Harms screw (257.9 N) (p<0.05). The pullout strength of S-PAS was 720.3 N, which was also significantly greater than that of the unicortical Harms screw (p<0.05). Conclusion: The via-PAS and S-PAS are valid surgical options, even in elderly patients. Along with sufficient biomechanical strength, the S-PAS screw prevents VAI.

Beneficial Potential of Casein Hydrolysate Containing Val-Pro-Pro and Ile-Pro-Pro on Central Blood Pressure and Hemodynamic Index: A Preliminary Study

Teppei Nakamura,Jun Mizutani,Kouichi Sasaki,Naoyuki Yamamoto,Kenji Takazawa 한국식품영양과학회 2009 Journal of medicinal food Vol.12 No.6

Pharmaceutical angiotensin-converting enzyme (ACE) inhibitors have been shown to reduce arterial stiffness; the possible effect of food-derived putative ACE inhibitory peptides on this degenerative process, however, has not been reported. In the present study, casein hydrolysate containing the lactotripeptides, Val-Pro-Pro (VPP) and Ile-Pro-Pro (IPP), which has been found to have an antihypertensive effect in a number of clinical studies, was investigated for its ability to improve hemodynamic parameters, including central systolic blood pressure (cSBP), in hypertensive subjects. Twelve hypertensive subjects who were not on prescribed medication were monitored for various hemodynamic parameters, including brachial blood pressure (peripheral blood pressure), cSBP, and augmentation index (AI), at the start and then after 3, 6, and 9 weeks of a daily treatment comprising four tablets containing VPP and IPP. Compared with basal levels, treatment with casein hydrolysate for 6 and/or 9 weeks showed a significant reduction in peripheral systolic and diastolic blood pressure, AI, and cSBP, but not in heart rate or pulse pressure. cSBP showed a reduction sooner and greater (−21.8mm Hg) than did brachial systolic blood pressure (−16.4mm Hg) during the 9-week treatment. Although small and not placebo-controlled, this study suggests that continuous intake of VPP and IPP might have the potential to improve arterial stiffness as well as cSBP and peripheral brachial blood pressure.

Segmental Arteries and Veins at Higher Lumbar Levels Can Intersect the Adjacent Caudal Intervertebral Disc in the Anterior Part of the Spinal Column: A Cadaveric Analysis

Yagi Kiyoshi,Suzuki Nobuyuki,Mizutani Jun,Kato Kenji,Kondo Akira,Waseda Yuya,Goto Yuta,Murakami Hideki 대한척추외과학회 2022 Asian Spine Journal Vol.16 No.1

Study Design: A cadaveric study.Purpose: To investigate the anatomical features of segmental arteries and veins in the anterior part of the spinal column to prevent segmental vessel injury.Overview of Literature: The lateral transpsoas approach to the lumbar intervertebral discs (IVD) is associated with the risk of segmental vessel injury. Previous studies have described the vascular anatomy on the lateral part of the vertebral body. However, there are no studies that describe the segmental vessels on its anterior aspect. Here, we report the important anatomical features of the segmental arteries and veins that can intersect the anterior part of the IVD. These vessels are considered at risk of vascular injury when placing the anterior retractors during lateral lumbar interbody fusion or cutting the anterior longitudinal ligament during anterior column realignment.Methods: Five formalin-embalmed human cadavers were used. We assessed the proportion of segmental arteries and veins that intersected the IVD in the L2–L5 range and their course on the anterior part of the spinal column.Results: The segmental arteries and veins commonly intersect the anterior part of the IVD (artery, 28.1%; vein, 42.1%). Seven of 10 (70%) segmental arteries at L2 intersected the IVD, but only one artery intersected the IVD at L3 and L4. The proportions of segmental veins that intersected the IVD were 60%, 50%, and 16.7% at L2, L3, and L4, respectively.Conclusions: The segmental arteries and veins frequently intersect the IVD in the anterior part of the spinal column. Therefore, it is necessary to consider these individual anatomical features to prevent vascular damage during lateral lumbar interbody fusion surgery.

Impact of Extra-Corporeal Membrane Oxygenation and Blood Purification Therapy on Early Mobilization in the Intensive Care Unit: Retrospective Cohort Study

Watanabe Shinichi,Iida Yuki,Hirasawa Jun,Naito Yuji,Mizutani Motoki,Uemura Akihiro,Nishimura Shogo,Suzuki Keisuke,Morita Yasunari 대한재활의학회 2023 Annals of Rehabilitation Medicine Vol.47 No.3

Objective: To investigate the effect on early mobilization in patients undergoing extra-corporeal membrane oxygenation (ECMO) and acute blood purification therapy in the intensive care unit (ICU).Methods: We conducted this multicenter retrospective cohort study by collecting data from six ICUs in Japan. Consecutive patients who were admitted to the ICU, aged ≥18 years, and received mechanical ventilation for >48 hours were eligible. The analyzed were divided into two groups: ECMO/blood purification or control group. Clinical outcomes; time to first mobilization, number of total ICU rehabilitations, mean and highest ICU mobility scale (IMS); and daily barrier changes were also investigated.Results: A total of 204 patients were included in the analysis, 43 in the ECMO/blood purification group and 161 in the control group. In comparison of clinical outcome, the ECMO/blood purification group had a significantly longer time to first mobilization: ECMO/blood purification group 6 vs. control group 4 (p=0.003), higher number of total ICU rehabilitations: 6 vs. 5 (p=0.042), lower mean: 0 vs. 1 (p=0.043) and highest IMS: 2 vs. 3 (p=0.039) during ICU stay. Circulatory factor were most frequently described as barriers to early mobilization on days 1 (51%), 2 (47%), and 3 (26%). On days 4 to 7, the most frequently described barrier was consciousness factors (21%, 16%, 19%, and 21%, respectively)Conclusion: The results of this study comparing the ECMO/blood purification group and the untreated group in the ICU showed that the ECMO/blood purification group had significantly longer days to mobilization and significantly lower mean and highest IMS.

p38 Mitogen-Activated Protein Kinase Is Involved in Interleukin-6 Secretion from Human Ligamentum Flavum–Derived Cells Stimulated by Tumor Necrosis Factor-α

Yagi Kiyoshi,Goto Yuta,Kato Kenji,Suzuki Nobuyuki,Kondo Akira,Waseda Yuya,Mizutani Jun,Kawaguchi Yohei,Joyo Yuji,Waguri-Nagaya Yuko,Murakami Hideki 대한척추외과학회 2021 Asian Spine Journal Vol.15 No.6

Study Design Human ligamentum flavum–derived cells (HFCs) were obtained from surgical samples for a basic experimental study. Purpose We sought to evaluate the inflammatory response of human ligamentum flavum cells to investigate hypertrophic changes occurring in the ligamentum flavum. Overview of Literature Lumbar spinal stenosis (LSS) is a disease commonly observed in the elderly. The number of patients with LSS has increased over time, yet the pathomechanisms of LSS still have not been fully elucidated. One of the clinical features of LSS is hypertrophy of the ligamentum flavum, which results in narrowing of the lumbar spinal canal. Some reports have suggested that ligamentum flavum hypertrophy is associated with inflammation and fibrosis; meanwhile, the p38 mitogen-activated protein (MAP) kinase is involved in the hypertrophy of human ligamentum flavum cells. Methods HFCs were obtained from patients with LSS who underwent surgery. HFCs were stimulated by tumor necrosis factor-α (TNF-α) and a p38 MAP kinase inhibitor, SB203580. Phosphorylation of the p38 MAP kinase was analyzed by western blotting. The concentration of interleukin-6 (IL-6) in the conditioned medium was measured by enzyme-linked immunoassay and IL-6 messenger RNA expression levels were determined by real-time polymerase chain reaction. Results TNF-α induced the phosphorylation of p38 MAP kinase in a time-dependent manner, which was suppressed by the p38 MAP kinase inhibitor, SB203580. TNF-α also stimulated IL-6 release in both a time- and dose-dependent manner. On its own, SB203580 did not stimulate IL-6 secretion from HFCs; however, it dramatically suppressed the degree of IL-6 release stimulated by TNF-α from HFCs. Conclusions This is the first report suggesting that TNF-α stimulates the gene expression and protein secretion of IL-6 via p38 MAP kinase in HFCs. A noted association between tissue hypertrophy and inflammation suggests that the p38 MAP kinase inflammatory pathway may be a therapeutic molecular target for LSS.