Tsukuba, Japan
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Mutsuzaki H.,Ibaraki Prefectural University of Health Sciences | Fujie H.,Tokyo Metroplitan University | Nakajima H.,Ibaraki University | Fukagawa M.,Tokyo Metroplitan University | And 2 more authors.
Orthopaedics and Traumatology: Surgery and Research | Year: 2017

Background: Calcium phosphate (CaP)-hybridized tendon grafts improved biomechanical function compared with untreated grafts after single-bundle (SB) anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to compare the biomechanical function between anatomic double-bundle (DB) and single-bundle (SB) ACL reconstructions using CaP-hybridized tendon grafts at 6 months postoperatively in goats. Hypothesis: We hypothesized that the postoperative biomechanical function in the DB group will be better than that in the SB group. Materials and methods: Knee kinematics and in situ forces in the grafts under applied anterior tibial load (ATL) of 50. N and internal tibial torque (ITT) of 2.0 Nm at full extension, and 60° and 90° of knee flexion, and the histology of the tendon-bone interface were compared between the DB group (n = 6) and SB group (n = 6). Results: The in situ forces under ATL in the DB group at full extension and 90°of knee flexion were greater than those in the SB group. The in situ forces under ITT in the DB group at full extension and 60°of knee flexion were greater than those in the SB group. The in situ forces on the posterolateral bundle of the grafts under ATL and ITT in the DB group at full knee extension were greater than those on the posterior half of the grafts in the SB group. The histology did not differ significantly between the groups. Conclusions: Although CaP-hybridized tendon grafts were used in both groups, the in situ forces under ATL and ITT in the DB group were greater than those in the SB group at 6 months postoperatively. The posterolateral bundle of the grafts in the DB group acted effectively against both ATL and ITT at full extension. The tendon-to-bone healing was similar in both groups. Study design: Controlled laboratory study. Level 2. © 2017 Elsevier Masson SAS.


Mutsuzaki H.,Ibaraki Prefectural University of Health Sciences | Nakajima H.,Ibaraki University | Wadano Y.,Ibaraki Prefectural University of Health Sciences | Furuhata S.,Ibaraki University | Sakane M.,Tsukuba Gakuen Hospital
International Journal of Molecular Sciences | Year: 2017

This study examined the influence of immobilization on chondrocyte apoptosis and histological features of the anterior cruciate ligament (ACL) insertion and knee articular cartilage in rabbits. Forty-eight male Japanese white rabbits were assigned to an immobilization (n = 24) or sham (n = 24) group. Rabbits in the immobilization group underwent complete unilateral surgical knee immobilization and rabbits in the sham group underwent a sham surgery. The average thickness of the glycosaminoglycan (GAG) stained red area by safranin O staining, the chondrocyte apoptosis rate and the chondrocyte proliferation rate in the cartilage layer in the ACL insertion and the articular cartilage of the medial tibial condyle were measured at one, two, four and eight weeks in six animals from each group. In the ACL insertion, the chondrocyte apoptosis rate was higher in the immobilization group than in the sham group at two and eight weeks after surgery (p < 0.05). The chondrocyte proliferation rate gradually decreased from two weeks to eight weeks in the immobilization group. The GAG layer was thinner in the immobilization group than in the sham group at two, four and eight weeks after surgery (p < 0.05). In the articular cartilage, the chondrocyte apoptosis rate in the immobilization group was higher than in the sham group at four and eight weeks after surgery (p < 0.05). The GAG layer was significantly thinner in the immobilization group than that in the sham group at four and eight weeks after surgery (p < 0.05). Knee immobilization significantly increased chondrocyte apoptosis at two and eight weeks after surgery in the ACL insertion and at four and eight weeks after surgery in the articular cartilage of the medial tibial condyle, and decreased GAG layer thickness from two to eight weeks after surgery in the ACL insertion and from four to eight weeks after surgery in the articular cartilage. © 2017 by the authors; licensee MDPI, Basel, Switzerland.


PubMed | Tsukuba Gakuen Hospital, Kensei General Hospital, University of Tsukuba, Mito Kyodo General Hospital and 2 more.
Type: Journal Article | Journal: Asian spine journal | Year: 2016

Retrospective, radiological study.To determine the relationship between clinical symptoms and the extent of tumor occupation of the spinal canal by cauda equina schwannoma.Little is known about the relationship between the size of tumors of the cauda equina and the manifestation of clinical symptoms. We analyzed this relationship by estimating the percentage of tumor occupation (PTO) in the spinal canal in cauda equina schwannomas and by correlating this parameter with the presence and severity of clinical symptoms.Twenty-two patients (9 men and 13 women; age, 19-79 years; mean age, 55.3 years) who were radiologically diagnosed with schwannomas of the cauda equina between April 2004 and July 2014 were retrospectively analyzed. PTO was measured in axial and sagittal magnetic resonance imaging slices in which the cross-sectional area of the tumor was the largest. Data regarding clinical symptoms and results of physical examinations were collected from patient medical records. PTO differences between symptom-positive and -negative groups were analyzed for each variable.In the 4 cases in which tumor presence was not related to clinical symptoms, PTO was 5%-10% (mean, 9%) in axial slices and 23%-31% (mean, 30%) in sagittal slices. In the 18 cases in which symptoms were associated with the tumor, PTO was 11%-86% (mean, 50%) in axial slices and 43%-88% (mean, 71%) in sagittal slices. PTO in axial slices was significantly higher in the presence of Djrine symptoms and/or muscle weakness, a positive straight leg raise test, and a positive Kemp sign.PTO >20% in axial slices and >40% in sagittal slices can be an indication of symptomatic cauda equina schwannoma.


PubMed | Tsukuba Gakuen Hospital, Kensei General Hospital, University of Tsukuba, Jikei University School of Medicine and 8 more.
Type: Journal Article | Journal: PloS one | Year: 2016

The incidence of post-infectious glomerulonephritis (PIGN) in developed countries has decreased over the last 50 years. Here we identified the trends of the incidence of PIGN in Japan during the past four decades.We explored the frequency, clinicopathological findings, and prognosis of PIGN based on 6,369 cases from the Renal Biopsy Database of our institute in the Kanto region of Japan, diagnosed histologically from 1976 to 2009.The numbers of PIGN cases were 131 (2.1%) in total, and 2.4%, 1.1%, 2.6% and 2.1% identified in the 1970s, 1980s, 1990s, and 2000s, respectively. Acute glomerulonephritis (AGN), including post-streptococcal glomerulonephritis (PSGN), accounted for almost all of the PIGN cases in the 1970s, but decreased to approx. 40%-50% since the 1990s. In the 1990s, Staphylococcus aureus infection-related nephritis (SARN) showed a rapid increase in rate, reaching 30%. The incidence of hepatitis C virus infection-associated GN (HCVGN) has increased since the 1990s. The average age at onset rose from 33 to 51 years over the study period. These transitions can be summarized as increases in SARN and HCVGN and decreases in PSGN and other types of AGN, since SARN and HCVGN have older onsets compared to PSGN and other AGN types. The clinicopathological features were marked for each PIGN. Regarding the prognosis, the renal death rates of both the SARN and HCVGN groups were significantly higher than those of other PIGN.Based on our analysis of the Renal Biopsy Database, the incidence of PIGN in Japan reached its peak in the 1990s. The temporal changes in the incidence of PIGN reflected the trends in infectious diseases of each decade and the continual aging of the population, with a related higher susceptibility to infections.


Fujita M.,Tsukuba Gakuen Hospital | Sato K.,Glaxosmithkline | Nishioka H.,Glaxosmithkline | Sakai F.,Saitama International Headache Center
Cephalalgia | Year: 2014

Objective: The objective of this article is to evaluate the efficacy and tolerability of two doses of oral sumatriptan vs placebo in the acute treatment of migraine in children and adolescents. Background: Currently, there is no approved prescription medication in Japan for the treatment of migraine in children and adolescents. Methods: This was a multicenter, outpatient, single-attack, double-blind, randomized, placebo-controlled, parallel-group study. Eligible patients were children and adolescents aged 10 to 17 years diagnosed with migraine with or without aura (ICHD-II criteria 1.1 or 1.2) from 17 centers. They were randomized to receive sumatriptan 25 mg, 50 mg or placebo (1:1:2). The primary efficacy endpoint was headache relief by two grades on a five-grade scale at two hours post-dose. Results: A total of 178 patients from 17 centers in Japan were enrolled and randomized to an investigational product in double-blind fashion. Of these, 144 patients self-treated a single migraine attack, and all provided a post-dose efficacy assessment and completed the study. The percentage of patients in the full analysis set (FAS) population who report pain relief at two hours post-treatment for the primary endpoint was higher in the placebo group than in the pooled sumatriptan group (38.6% vs 31.1%, 95% CI: -23.02 to 8.04, p=0.345). The percentage of patients in the FAS population who reported pain relief at four hours post-dose was higher in the pooled sumatriptan group (63.5%) than in the placebo group (51.4%) but failed to achieve statistical significance (p=0.142). At four hours post-dose, percentages of patients who were pain free or had complete relief of photophobia or phonophobia were numerically higher in the sumatriptan pooled group compared to placebo. Both doses of oral sumatriptan were well tolerated. No adverse events (AEs) were serious or led to study withdrawal. The most common AEs were somnolence in 6% (two patients) in the sumatriptan 25 mg treatment group and chest discomfort in 7% (three patients) in the sumatriptan 50 mg treatment group. Conclusions: There was no statistically significant improvement between the sumatriptan pooled group and the placebo group for pain relief at two hours. Oral sumatriptan was well tolerated. © 2013 International Headache Society.


Kurihara Y.,University of Tsukuba | Hitomi S.,University of Tsukuba | Oishi T.,Tokyo Medical University | Kondo T.,Tsuchiura Kyodo General Hospital | And 3 more authors.
Journal of Infection and Chemotherapy | Year: 2013

Although Proteus mirabilis is a common human pathogen, bacteremia caused by the organism, especially strains producing extended-spectrum beta-lactamase (ESBL), has rarely been investigated. We examined 64 cases of P. mirabilis bacteremia identified in the Minami Ibaraki Area, Japan, between 2001 and 2010 and compared the characteristics of cases with ESBL-producing and ESBL-non-producing strains (13 and 51 cases, respectively). All ESBL-producing strains with the gene encoding the CTX-M-2-group were genetically nonidentical. Isolation of ESBL-producing strains was significantly associated with onset in a hospital (p = 0.030), receiving hemodialysis (p = 0.0050), and previous antibiotic use within 1 month (p = 0.036; especially penicillin and/or cephalosporin (p = 0.010) and fluoroquinolone (p = 0.0069)). Isolation was also associated with inappropriate antibiotic therapy on the 1st and 4th days (p = 0.011 and 0.032, respectively) but not with mortality on the 30th day. These findings indicate that, for P. mirabilis bacteremia, isolation of ESBL-producing strains causes delay of initiating appropriate antimicrobial therapy but may not be associated with mortality. © 2013 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases.


PubMed | Tsukuba Gakuen Hospital, Tokyo Metroplitan University, Ibaraki Prefectural University of Health Sciences and Ibaraki University
Type: Journal Article | Journal: Orthopaedic journal of sports medicine | Year: 2016

We previously developed a novel technique using an alternate soaking process that improves tendon-bone healing by hybridizing the tendon graft with calcium phosphate (CaP). However, the effects of the CaP-hybridized tendon graft on anatomic single-bundle anterior cruciate ligament (ACL) reconstruction remain unclear.To determine the effects of CaP-hybridized tendon grafts compared with untreated tendon grafts 6 months after anatomic single-bundle ACL reconstruction using a goat model.Controlled laboratory study.Animals were divided into a CaP group (n = 5 goats) and a control group (n = 5 goats), and we analyzed (1) knee kinematics and in situ forces under applied anterior tibial loads of 50 N and internal tibial torque of 2.0 Nm in the grafts at full extension and at 60 and 90 of knee flexion, (2) the mean percentage of bone tunnel enlargement using computed tomography (CT), and (3) the histology of the tendon-bone interface.The in situ forces under applied anterior tibial loads of 50 N at 60 and 90 of knee flexion in the CaP group were greater than those in the control group (P < .05). The red safranin-O-stained area, indicating glycosaminoglycans in the cartilage layers at the joint aperture sites of the anterior femoral and posterior tibial bone tunnel, was greater in the CaP group than that in the control group (P < .05). The lengths of the nonbonding gap area between the anterior femoral and posterior tibial bone tunnels in the control group were greater than those in the CaP group (P < .05). No significant difference could be detected in the mean percentage of bone tunnel enlargement between the 2 groups.The CaP-hybridized tendon graft enhanced tendon-bone healing at the joint aperture site in both anterior femoral and posterior tibial tunnels 6 months after anatomic single-bundle ACL reconstruction in goats. The in situ forces under applied anterior tibial loads at greater flexion angles in the CaP group increased compared with controls.Anatomic single-bundle ACL reconstruction using CaP-hybridized tendon grafts may lead to better postoperative knee function.


PubMed | Ibaraki University, Ibaraki Prefectural University of Health Sciences and Tsukuba Gakuen Hospital
Type: Journal Article | Journal: International journal of molecular sciences | Year: 2017

This study examined the influence of immobilization on chondrocyte apoptosis and histological features of the anterior cruciate ligament (ACL) insertion and knee articular cartilage in rabbits. Forty-eight male Japanese white rabbits were assigned to an immobilization (


Takabayashi N.,Tsukuba Gakuen Hospital | Hiraoka T.,University of Tsukuba | Kiuchi T.,Tsukuba Gakuen Hospital | Oshika T.,University of Tsukuba
Japanese Journal of Ophthalmology | Year: 2013

Purpose: To investigate the influence of decorative lenses on ocular wavefront aberrations. Methods: A wavefront analyzer was used to measure higher-order aberrations (HOAs) in 20 right eyes of 20 participants while they were wearing Vistacon contact lenses of different designs, namely, clear 1-day Acuvue, ring-design circle 1-day Acuvue Define (Accent style), or spoke-design circle 1-day Acuvue Define (Vivid style). All of these lenses are made of the same materials and have the same lens parameters, except for the tinted design. HOAs induced by each contact lens were measured for 4- and 6-mm pupils. The coma-like, spherical-like, and total HOAs of each lens type were compared. HOAs of well- and poorly fitting lenses were also compared. Results: For a 4-mm pupil, the HOAs of the three lens types did not differ significantly. For the 6-mm pupil, coma-like and total HOAs were significantly larger with decorative lenses than with clear lenses (P < 0.05, Bonferroni test). No significant differences were observed between the two types of decorative lenses. Poorly fitting decorative lenses showed significantly larger HOAs than did well-fitting decorative lenses. Conclusions: Poorly fitting decorative lenses may reduce the quality of vision. Consequently, care should be taken that these lenses are properly centered. © 2013 Japanese Ophthalmological Society.


Ishii K.,University of Tsukuba | Hiraoka T.,University of Tsukuba | Kaji Y.,University of Tsukuba | Sakata N.,University of Tsukuba | And 2 more authors.
International Ophthalmology | Year: 2011

Background Klebsiella pneumoniae endophthalmitis is rare and despite immediate management, visual outcome is generally poor. We report a case of endogenous K. pneumoniae endophthalmitis that was treated successfully. Case An 80-year-old woman with a liver abscess was diagnosed at an early stage with endogenous K. pneumoniae endophthalmitis. She underwent par plana vitrectomy and lensectomy within 8 h after the onset of ocular symptoms. Secondary implantation of a sulcus-fixated intra-ocular lens (IOL) was performed 12 months later. Final visual acuity OS was 20/20. Conclusions The present case highlights the potential benefit of early and broad vitrectomy with lensectomy in the management of endogenous K. pneumoniae endophthalmitis. © 2010 Springer Science+Business Media B.V.

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