発育期分離すべりモデルラットにおける下位椎体変形修復の骨化様式

Study design: A study using rat spondylolisthesis models. Objective: To elucidate the mechanism for correction of vertebral rounding deformity. Summary of Background Data: Vertebral rounding deformity is the strongest risk factor for high-grade slippage associated with spondylolisthesis in adolescents. We previously reported that inadequate endochondral ossification of the anterior upper corner of the vertebral growth plate in response to mechanical stress could be the pathological mechanism of vertebral rounding deformity. Methods: We created a model of spondylolisthesis using 4-week-old rats. They were divided into a tail suspension group that underwent tail suspension to decrease mechanical stress starting at 2 weeks postoperatively and a ground control group with no intervention. Radiographs and micro-computed tomography scans were obtained once weekly for 6 weeks postoperatively. The lumbar spines were then harvested for histological analysis. Immunohistochemical studies detected types I, II, and X collagen in the growth plate cartilage. Bone histomorphometrical analysis was also performed. Results: Radiological and histological evidence in the ground control group showed progress the rounding deformity with time as previously reported. Formation of normal cancellous bone was observed radiologically over time in the tail suspension group, indicating correction of rounding deformity. Histologically, the site showing radiological evidence of correction was derived from cartilage tissue. After starting tail suspension, the growth plate stained positive for type X collagen and the corrected site stained for types II and X collagen in a mosaic pattern. Chondrocytes expressing types I and II collagen and tartrate-resistant acid phosphatase-positive cells were also present at the corrected site. Histomorphometrically, more endochondral bone was detected at the corrected site than in the posterior aspect of the normal growth plate. Conclusion: Correction of vertebral rounding deformity was associated with improvement of chondrocyte differentiation, furthermore, there is possible involvement of a third mechanism, namely transchondroid bone ossification.It is possible to correct the rounding deformity of the vertebral body associated with isthmus slippage by decrease the load on the vertebral body in pediatric patients. In addition to improved chondrocyte differentiation and promotion of redifferentiation, there is possible involvement of a third mechanism, namely transchondroid bone ossification

Fluoroquinolone resistance in extended-spectrum β-lactamase-producing Klebsiella pneumoniae in a Japanese tertiary hospital: silent shifting to CTX-M-15-producing K. pneumoniae

Purpose. Fluoroquinolone resistance (FQ-r) in extended-spectrum β-lactamase (ESBL) producers is an urgent health concern in countries where ESBL-producing K. pneumoniae (ESBL-Kpn) is prevalent. We investigated FQ-r in Japan where ESBL-Kpn is less prevalent. Methodology. Clinical ESBL-Kpn isolates from 2011 to 2013 were collected in Nagasaki University Hospital. The ESBL genotypes included CTX-M-15, and the mechanisms of FQ-r through plasmid-mediated quinolone resistance (PMQR) and mutations in quinolone resistance-determining regions (QRDRs) were examined. Clonality was analysed by enterobacterial repetitive intergenic consensus (ERIC)-PCR and multi-locus sequence typing was performed on selected isolates. Results/Key findings. Thirty ESBL-Kpn isolates, including seven levofloxacin-resistant isolates, were obtained from different patients. An increase in CTX-M-15-producing strains was observed during the study period (0/11 in 2011, 3/8 in 2012, and 5/11 in 2013). PMQR was detected in 53.3?% of the isolates and aac-(6′)-Ib-cr was the most common (36.7?%). ST15 was observed in 60.0?% of the isolates, and for the most predominant ERIC-PCR profiles, 62.5?% of the isolates possessed the CTX-M-15 genotype and 71.4?% were levofloxacin-resistant. Levofloxacin-resistance was significantly more common in CTX-M-15 isolates (62.5?%) compared to non-CTX-M-15 isolates (9.1?%). Three QRDR mutations and aac(6′)-Ib-cr, but not qnrB and qnrS, were significantly enriched in the CTX-M-15 isolates (100.0?%) compared to the non-CTX-M-15 isolates (13.6?%). Conclusion. Cumulatively, these results indicate that the epidemic strain, the CTX-M-15-producing K. pneumoniae ST15, is covertly spreading even when ESBL producers are not prevalent. Monitoring these epidemic strains and ESBLs in general is important for quickly identifying health crises and minimizing future risks from FQ-r ESBL-Kpn

State of the Art : Elbow Arthroscopy : Review of the Literature and Application for Osteochondritis Dissecans of the Capitellum

Elbow arthroscopy has become a safe and effective treatment option for a number of elbow disorders. The most rewarding and successful indication is the removal of loose bodies. Loose bodies are often a result of osteochondritis dissecans (OCD) of the　capitellum, and arthroscopy in this case is useful for performing debridement, thereby eliminating the need for a more extensive open procedure associated with complications. In this review, we describe our arthroscopic technique for OCD of the capitellum. We usually conduct arthroscopy in the supine position, and use 2.9-mm arthroscopes of 30°and 70°. The 70°arthroscope provides a greater operative field than the 30°arthroscope. Arthroscopic treatment for OCD may require 2 anterior and 2 posterior portals. Loose bodies are commonly found in the radial fossa, coronoid fossa, and in the olecranon fossa. Once the loose bodies are removed, all unstable cartilage of the capitellum lesion is removed to create a stable bed. If any sclerotic changes to the lesion bed are observed, we create microfractures in the lesion bed. The most significant complication in arthroplasty is neurovascular injury. However, we have never experienced this devastating complication, which can be avoided by paying careful attention to detail

State of the Art : Transforaminal Approach for Percutaneous Endoscopic Lumbar Discectomy under Local Anesthesia

Minimally invasive percutaneous endoscopic discectomy (PED) with a transforaminal approach under local anesthesia was started in the late 20th century. As the procedure requires a skin incision of only 8mm, it is the least invasive disc surgery procedure at present, and owing to advances in instruments and optics, the use of this technique has gradually spread. In Japan, Dr. Dezawa from Teikyo University Mizonokuchi Hospital introduced this technique in 2003. Thanks to his efforts, the number of surgeons who can perform PED has increased, although the number of active PED surgeons is still only around 20. The first author (K.S.) started PED in 2010. In this review article, we explain the state-of-the-art PED transforaminal technique for minimally invasive disc surgery and present three successful cases

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

A Rare Case of Progressive Palsy of the Lower Leg during Percutaneous Endoscopic Lumbar Discectomy via a Transforaminal Approach

Percutaneous endoscopic discectomy (PED) for lumbar disc herniation is gaining popularity with the transforaminal (TF) approach preferred because it allows surgery under local anesthesia and preserves the spinal muscles. Although this procedure has some characteristic complications, it is rare for PED to be converted to conventional open surgery due to worsening of symptoms intraoperatively. Here, we report PED via the TF approach that required conversion to open surgery. A 20-year-old man with a large disc herniation at L3/4 developed severe progressive leg pain and muscle weakness of the left leg intraoperatively. Magnetic resonance imaging revealed that the size of the herniation was unchanged and the endoscope did not reach the herniated mass. We converted to open surgery, and the patient’s postoperative course was favorable. We discuss the reasons for failure of the approach and suggest planning for an appropriate foraminoplasty to avoid the potential need for conversion to open surgery

An Experimental Investigation of the MUSIC-based Wireless Position Location using LCX antenna at 5GHz band

2019 19th International Symposium on Communications and Information Technologies (ISCIT)n recent years, a wireless system using LCX (Leaky CoXial cable) antenna has been studied as a method of locating a wireless terminal in indoor. As typical method, the IFFT (Inverse Fast Fourier Transform) of the channel frequency response is available for obtaining channel impulse response, then, local position can be estimated based on the TDOA (Time Difference Of Arrival). Although spacial resolution of positioning is limited by measured bandwidth of frequency response, the MUSIC (MUltiple SIgnal Classification) algorithm has been proposed to overcome its limitation [1], [2]. Previous study [3] employed the MUSIC algorithm in 2 by 2 LCX antenna system at 2.4 GHz band, and its precision has been evaluated experimentally. Since the LCX antenna has newly developed for 5 GHz, positioning performance at 5GHz band has evaluated in this paper. After the channel response was measured in the radio anechoic chamber, and its precision is experimentally evaluated