Robust Control of Water Hydraulic Servo Motor System Using Sliding Mode Control with Disturbance Observer

Kazuhisa ITO,Hidekazu TAKAHASH,Shigeru IKEO,Koji TAKAHASHI 제어로봇시스템학회 2006 제어로봇시스템학회 국제학술대회 논문집 Vol.2006 No.10

Effects of Val-Pro-Pro and Ile-Pro-Pro on Nondipper Patients: A Preliminary Study

Mari Takahashi Kurosawa,Yasunori Nakamura,Naoyuki Yamamoto,Kazuhisa Yamada,Toshiro Iketani 한국식품영양과학회 2011 Journal of medicinal food Vol.14 No.5

Much clinical evidence on the antihypertensive effects of the milk-derived antihypertensive peptides Val-Pro-Pro and Ile-Pro-Pro (lactotripeptides) has been reported. However, circadian rhythm effects determined by ambulatory blood pressure monitoring (ABPM) to eliminate the confounding influence of the white-coat effect have not been fully studied. Twelve hypertensive patients not receiving antihypertensive medication (2 men, 10 women; mean age±standard deviation, 63.5±8.3 years) who had been visiting our clinic for more than 1 year participated in this study. Mean (±standard deviation) systolic blood pressure (SBP) and diastolic blood pressure (DBP) were 142.4±2.6 and 83.5±6.4 mm Hg, respectively, at the first office visit. After patients ingested a fermented milk product containing antihypertensive peptides (2.53 mg Val-Pro-Pro; 1.52 mg Ile-Pro-Pro) for more than 4 weeks, both office SBP and DBP were significantly reduced to a mean (±standard deviation) of 133.3±7.0 mm Hg and 76.5±8.4 mm Hg (P<.001 and P<.005 by paired t-test), respectively. The 24-hour SBP and DBP determined by ABPM were reduced from 127.3±2.4 and 78.7±2.3 mm Hg to 120.2±2.4 and 75.0±2.2 mm Hg (P<.001 and P<.05), respectively. Awake-time SBP (08:00–21:00), night-time SBP (0:00–05:00), and early-morning SBP (06:00–07:00) were reduced from 130.9±2.4 to 123.3±2.3 mm Hg, 118.7±2.9 to 113.2±3.4 mm Hg, and 132.8±4.3 to 122.4±3.9 mm Hg (by paired t-test: P<.001, P<.05, and P<.05), respectively. As seen with DBP measured by ABPM, 24-hour DBP and awake-time DBP were significantly reduced from 78.7±2.3 to 75.0±2.2 mm Hg and 82.1±2.5 to 77.3±2.2 mm Hg (P<.05 and P<.01), respectively. Office BP and 24-hour blood pressure did not significantly differ between the dipper and nondipper groups at baseline. However, after treatment, night-time and early-morning blood pressure were significantly reduced from baseline in the nondipper group (−8.5±2.5 and −15.6±3.7 mm Hg; P<.05 and P<.01, respectively) but not in the dipper group (−2.5±3.6 and −1.2±4.7 mm Hg; P not significant), and the reduction in early-morning blood pressure significantly differed between the groups (P<.05). These results suggest that Val-Pro-Pro and Ile-Pro-Pro decrease blood pressure in patients with stage I hypertension and result not only in lower blood pressure at night-time but also in lower early-morning SBP in nondipper patients.

From tumor hypoxia to cancer progression

Fariz Nurwidya,Fumiyuki Takahashi,Kunihiko Minakata,Akiko Murakami,Kazuhisa Takahashi 대한해부학회 2012 Anatomy & Cell Biology Vol.45 No.2

Hypoxia, defined as a decrease of tissue oxygen levels, represents a fundamental pathophysiological condition in the microenvironment of solid tumors. Tumor hypoxia is known to be associated with radio/chemo-resistance and metastasis that eventually lead to cancer progression contributing to poor prognosis in cancer patients. Among transcription factors that accumulated under hypoxic conditions, hypoxia-inducible factor-1 (HIF-1) is a master transcription factor that has received the most intense attention in this field of research due to its capacity to modulate several hundred genes. With a clearer understanding of the HIF-1 pathway, efforts are directed at manipulation of this complex genetic process in order to ultimately decrease cellular HIF-1 levels. Some novel agents have been shown to have HIF-1 inhibition activity through a variety of molecular mechanisms and have provided promising results in the preclinical setting.

Epithelial Mesenchymal Transition in Drug Resistance and Metastasis of Lung Cancer

Fariz Nurwidya,Fumiyuki Takahashi,Akiko Murakami,Kazuhisa Takahashi 대한암학회 2012 Cancer Research and Treatment Vol.44 No.3

Among all types of cancer, incidence of lung cancer remains the highest with regard to cancerrelated mortality. Problems contributing to recurrence of the disease include metastasis and drug resistance. Mounting evidence has demonstrated involvement of epithelial mesenchymal transition (EMT) in cancer progression. EMT is a critical mechanism ensuring tissue remodeling during morphogenesis of multicellular organisms. Therefore, understanding of the biology of this process for identification of potential EMT-targeted therapeutic strategies for the benefit cancer patients is necessary. This review describes recent evidence of EMT involvement in drug resistance and metastasis of cancers, with an emphasis on lung cancer.

Spinopelvic Alignment and Low Back Pain after Total Hip Replacement Arthroplasty in Patients with Severe Hip Osteoarthritis

Yawara Eguchi,Satoshi Iida,Chiho Suzuki,Yoshiyuki Shinada,Tomoko Shoji,Kazuhisa Takahashi,Seiji Ohtori 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.2

Study Design: Retrospective observational study. Purpose: We examined change in lumbrosacral spine alignment and low back pain (LBP) following total hip arthroplasty (THA) in patients with severe hip osteoarthritis (OA). Overview of Literature: Severe hip osteoarthritis has been reported to cause spine alignment abnormalities and low back pain, and it has been reported that low back pain is improved following THA. Methods: Our target population included 30 patients (29 female, mean age 63.5 years) with hip OA who underwent direct anterior approach THA. There were 12 cases with bilateral hip disease and 18 cases with unilateral osteoarthritis. Visual analogue scale (VAS) scores for LBP and coxalgia, the Roland-Morris Disability Questionnaire (RDQ), and the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) were assessed before and after surgery. Spinal alignment metrics were measured before and after surgery. Results: VAS for LBP change from preoperative to final postoperative observation was significantly improved (p <0.05), as was VAS for hip pain (p <0.001). RDQ improved significantly (p <0.01). All five domains of JOABPEQ were significantly improved (p <0.05). In terms of coronal alignment, lumbar scoliosis change from preoperative to last observation was significantly reduced (p <0.05). There were no significant changes in the sagittal alignment metrics. In addition, there was a correlation between before and after RDQ difference and before and after lumbar scoliosis difference (p <0.05). VAS for LBP (p <0.05) as well as RDQ (p <0.05) were significantly improved only in unilateral OA. Lumbar scoliosis was significantly improved in cases of unilateral OA (p <0.05), but alignment did not improve in cases of bilateral OA (p =0.29). Conclusions: The present study demonstrates improvements in VAS for LBP, RDQ, and all domains of JOABPEQ. There were also significant reductions in lumbar scoliosis and an observed correlation of RDQ improvement with lumbar scoliosis improvement. We were able to observe improvements in lumbar scoliosis and low back pain only in cases of unilateral OA. It has been suggested that the mechanism of low back pain improvement following THA is related to compensatory lumbar scoliosis improvement.

Modified Open-Door Laminoplasty Using a Ceramic Spacer and Suture Fixation for Cervical Myelopathy

Tomoyuki Ozawa,Tomoaki Toyone,Ryutaro Shiboi,Kunimasa Inada,Yasuhiro Oikawa,Kazuhisa Takahashi,Seiji Ohtori,Gen Inoue,Masayuki Miyagi,Tetsuhiro Ishikawa,Toshiyuki Shirahata,Yoshifumi Kudo,Katsunori In 연세대학교의과대학 2015 Yonsei medical journal Vol.56 No.6

Purpose: To introduce a new simple technique using suture anchors and ceramic spacers to stabilize the elevated laminae in open-door cervical laminoplasty. Although ceramic spacers were placed in the opened laminae and fixed with nylon threads in this series, it was occasionally difficult to fix the nylon threads to the lateral mass. Materials and Methods: Study 1: A preliminary study was conducted using a suture anchor system. Sixteen consecutive patients who underwent surgery for cervical myelopathy were prospectively examined. Study 2: The second study was performed prospectivelyto evaluate the feasibility of this new technique based on the result of the preliminary study. Clinical outcomes were examined in 45 consecutive patients [cervical spondylotic myelopathy (CSM)] and 43 consecutive patients (OPLL). The Japanese Orthopedic Association scoring system (JOA score), axial neck pain, and radiological findings were analyzed. Results: 1) In one case, re-operation was necessary due to dislodgement of the ceramic spacer following rupture of the thread. 2) In all patients, postoperative CT scans showed that the anchors were securely inserted into the bone. In the CSM group, the average JOA score improved from 9.5 points preoperatively to 13.3 at follow-up (recovery 51%). In the OPLL group, the average JOA score improvedfrom 10.1 (5–14) points preoperatively to 14.4 (11–16) at follow-up (recovery 62%). There were no serious complications. Conclusion: The use of the suture anchor system made it unnecessary to create a hole in the lateral mass and enabled reliable and faster fixation of the HA spacers in open-door laminoplasty.

Postoperative Increase in Occiput–C2 Angle Negatively Impacts Subaxial Lordosis after Occipito–Upper Cervical Posterior Fusion Surgery

Taigo Inada,Takeo Furuya,Koshiro Kamiya,Mitsutoshi Ota,Satoshi Maki,Takane Suzuki,Kazuhisa Takahashi,Masashi Yamazaki,Masaaki Aramomi,Chikato Mannoji,Masao Koda 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.4

Study Design: Retrospective case series. Purpose: To elucidate the impact of postoperative occiput–C2 (O–C2) angle change on subaxial cervical alignment. Overview of Literature: In the case of occipito–upper cervical fixation surgery, it is recommended that the O–C2 angle should be set larger than the preoperative value postoperatively. Methods: The present study included 17 patients who underwent occipito–upper cervical spine (above C4) posterior fixation surgery for atlantoaxial subluxation of various etiologies. Plain lateral cervical radiographs in a neutral position at standing were obtained and the O–C2 angle and subaxial lordosis angle (the angle between the endplates of the lowest instrumented vertebra (LIV) and C7 vertebrae) were measured preoperatively and postoperatively soon after surgery and ambulation and at the final follow-up visit. Results: There was a significant negative correlation between the average postoperative alteration of O–C2 angle (DO–C2) and the average postoperative alteration of subaxial lordosis angle (Dsubaxial lordosis angle) (r =–0.47, p =0.03). Conclusions: There was a negative correlation between DO–C2 and Dsubaxial lordosis angles. This suggests that decrease of midto lower-cervical lordosis acts as a compensatory mechanism for lordotic correction between the occiput and C2. In occipito-cervical fusion surgery, care must be taken to avoid excessive O–C2 angle correction because it might induce mid-to-lower cervical compensatory decrease of lordosis.

Neural Mechanisms of Discogenic Back Pain: How Does Nerve Growth Factor Play a Key Role?

Yasuchika Aoki,Seiji Ohtori,Koichi Nakagawa,Arata Nakajima,Gen Inoue,Masayuki Miyagi,Kazuhisa Takahashi 대한척추신경외과학회 2011 Neurospine Vol.8 No.2

It was reported that nerve fibers were present in the inner part of lumbar intervertebral discs from patients with discogenic pain. Because there are no nerve fibers in the inner part of annulus fibrosus in normal condition, this finding suggests nerve ingrowth into the disc may be a cause of discogenic pain. Disc degeneration is often asymptomatic, thus, to understand the differences between symptomatic and asymptomatic disc, it is necessary to understand the pathogenesis of discogenic pain. We recently revealed that over 90% of the nociceptive dorsal root ganglion (DRG) neurons innervating the disc are sensitive to nerve growth factor (NGF), which is related to inflammatory pain. This indicates that discogenic pain is closely related to inflammation and NGF may play a key role. The increase of inflammatory mediators in symptomatic discs has been reported; we therefore studied the effects of disc inflammation and found that it induces sensitization of disc-innervating neurons and nerve ingrowth into the disc. More recently, it was shown that annular rupture induces nerve ingrowth, an increase of inflammatory mediators in the disc, and upregulation of calcitonin gene-related peptide, a pain-related molecule in DRGs. These findings led us to believe that annular rupture triggers inflammation and nerve ingrowth, inflammatory mediators then further promote nerve ingrowth into the disc and sensitization of disc-innervating neurons, and discogenic pain finally becomes chronic. NGF, found in symptomatic discs, may act as a key factor in generating chronic discogenic pain by sensitizing disc-innervating neurons and stimulating nerve ingrowth into the disc.

Evaluation of Lumbar Intervertebral Disc Degeneration Using T1ρ and T2 Magnetic Resonance Imaging in a Rabbit Disc Injury Model

Tetsuhiro Ishikawa,Atsuya Watanabe,Hiroto Kamoda,Masayuki Miyagi,Gen Inoue,Kazuhisa Takahashi,Seiji Ohtori 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.2

Study Design: An in vivo histologic and magnetic resonance imaging (MRI) study of lumbar intervertebral disc (IVD) degeneration was conducted. Purpose: To clarify the sensitivity and efficacy of T1ρ/T2 mapping for IVD degeneration, the correlation between T1ρ/T2 mapping and degenerative grades and histological findings in the lumbar IVD were investigated. Overview of Literature: The early signs of IVD degeneration are proteoglycan loss, dehydration, and collagen degradation. Recently, several quantitative MRI techniques have been developed; T2 mapping can be used to evaluate hydration and collagen fiber integrity within cartilaginous tissue, and T1ρ mapping can be used to evaluate hydration and proteoglycan content. Methods: Using New Zealand White rabbits, annular punctures of the IVD were made 10 times at L2/3, 5 times at L3/4, and one time at L4/5 using an 18-gauge needle (n=6) or a 21-gauge needle (n=6). At 4 and 8 weeks post-surgery, MRI was performed including T1ρ and T2 mapping. The degree of IVD degeneration was macroscopically assessed using the Thompson grading system. All specimens were cut for hematoxylin and eosin, safranin-O, and toluidine blue staining. Results: Disc degeneration became more severe as the number of punctures increased and when the larger needle was used. T1ρ and T2 values were significantly different between grade 1 and grade 3 IVDs, grade 1 and grade 4 IVDs, grade 2 and grade 3 IVDs, and grade 2 and grade 4 IVDs (p <0.05). There was a significant difference between grade 1 and grade 2 IVDs only in terms of T1ρ values (p <0.05). Conclusions: T1ρ and T2 quantitative MRI could detect these small differences. Our results suggest that T1ρ and T2 mapping are sensitive to degenerative changes of lumbar IVDs and that T1ρ mapping can be used as a clinical tool to identify early IVD degeneration.

Prognostic differences among patients with different etiologies of acute exacerbation of chronic fibrotic idiopathic interstitial pneumonia

( Motoyasu Kato ),( Yuta Arai ),( Hiroaki Motomura ),( Issei Sumiyoshi ),( Yusuke Ochi ),( Junko Watanabe ),( Hiroaki Ihara ),( Shinsaku Togo ),( Shinichi Sasaki ),( Kazuhisa Takahashi ) 대한결핵 및 호흡기학회 2019 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.127 No.-

Background: Acute exacerbation of chronic fibrotic idiopathic interstitial pneumonia (AE-IIP) is associated with a high mortality rate. In 2016, the International Working Group classified the etiology of AE-IIP into idiopathic and triggered. Several factors can trigger AE-IIP; however, the triggers associated with the worst prognosis have not been identified. The aim of this study was to investigate the prognosis of patients with various types of AE-IIP, particularly infection-triggered, non-infection-triggered, and idiopathic AE-IIPs. Methods: We retrospectively collected data for 128 patients with chronic fibrotic IIP (CF-IIP) who were hospitalized because of respiratory failure during the period between April 2009 and March 2019 at Juntendo University Hospital. There were 79 patients who developed AE-IIP, and 21 patients who developed bacterial pneumonia combined with CF-IIP. AE-IIP was classified into idiopathic, infection-triggered, and non-infection-triggered. We analyzed differences in patient characteristics, examination findings, and prognosis among the types. Finally, we evaluated risk factors for early death due to AE-IIPs. Results: Idiopathic, infection-triggered, and non-infection-triggered AE-IIPs were diagnosed in 34, 25, and 20 patients, respectively. The survival time was significantly longer for bacterial pneumonia combined with IIP than for AE-IIP. Moreover, the survival time was significantly longer for infection-triggered AE-IIP than for idiopathic or non-infection-triggered AE-IIP. The mortality rate was significantly lower with infection-triggered AEIIP than with other types of AE-IIP. Finally, a multivariate analysis revealed that radiological findings at the time of onset of AE-IIPs and AE-IIP patterns were independent risk factors for early death. Conclusion: Our results suggest that patients with infection-triggered AE-IIP may have a better prognosis than those with other types of AE-IIP.