Comparisons of kinematics during stair motion in total knee arthroplasty: Single-radius versus J-curved designs

Background: Patients who undergo TKA continue to report difficulty in ascending and descending stairs. However, it is unknown how kinematic pattern TKA knees demonstrate during stair ascending and descending. The purpose of the present study was (1) to determine how kinematics TKA knees demonstrate during stair ascending and descending; (2) to investigate whether TKA kinematics during stair ambulation are different among designs of implants as well as during squatting.Methods: We analyzed twenty two knees (19 patients, all female) that implanted with single-radius PS TKA which was the Triathlon posterior stabilized knee prosthesis or the J-curved PS TKA which was the Legacy flex posterior stabilized knee prosthesis. Each patient performed stair ascending and descending at patient’s comfortable pace. We evaluated the kinematics of stair ascending and descending using 2-dimensional to 3-dimensional registration technique.Results: Anteroposterior translation was significantly less in single-radius PS TKA compared to J-curved PS TKA during stair ascending and descending. At foot strike, post-cam engagement was observed in all 11 knees implanted with single-radius PS TKA and in three of 11 knees with J-curved PS TKA during stair ascending.Conclusions: Single-radius design of the femoral component, constrained articulation and less posterior slope might lead to less anteroposterior translation of the femur during stair ascending and descending. Additionally, it is also associated with the stability that the post cam contact prevented the femur from moving anteroposterior before and after foot strike during stair ascending and escending. It should be necessary that the post cam mechanism is designed not only for inducing rollback motion, but also for controlling anteroposterior translation in mid-flexion range

Capping protein binding to actin in yeast: biochemical mechanism and physiological relevance

The mechanism by which capping protein (CP) binds barbed ends of actin filaments is not understood, and the physiological significance of CP binding to actin is not defined. The CP crystal structure suggests that the COOH-terminal regions of the CP α and β subunits bind to the barbed end. Using purified recombinant mutant yeast CP, we tested this model. CP lacking both COOH-terminal regions did not bind actin. The α COOH-terminal region was more important than that of β. The significance of CP's actin-binding activity in vivo was tested by determining how well CP actin-binding mutants rescued null mutant phenotypes. Rescue correlated well with capping activity, as did localization of CP to actin patches, indicating that capping is a physiological function for CP. Actin filaments of patches appear to be nucleated first, then capped with CP. The binding constants of yeast CP for actin suggest that actin capping in yeast is more dynamic than in vertebrates

マウスガードの自律神経活動への影響 : 瞳孔フラッシュ応答による定量的評価

Background:Recently, it has been reported that mouth guards (MGs), which reduce the incidence and severity of traumatic oral injuries in contact sports, may actually affect sports performance. We have observed that a majority of subjects showed improved dynamic visual acuity during head rotation when using a MG, but subjects who were unwilling to use a MG showed the opposite effect. Thus, we hypothesized that unpleasant sensations due to MGs may decrease sports performance.Methods:In this study, we measured autonomic nervous system activity to evaluate unpleasant sensations objectively and quantitatively by measuring the pupillary flash response (PFR) and heart rate variability (HRV), before, during, and after wearing 3- and 5-mm-thick custom-made MGs in 10 healthy subjects.Results:It was found that the 5-mm MG had a higher incidence of unpleasant sensations (50% of subjects) than did the 3-mm MG (10%). PFR (not HRV) analysis showed that both sympathetic and parasympathetic nervous system activities increased in subjects with unpleasant sensations.Conclusions:We suggest that the unpleasant sensation induced this unusual autonomic nervous system response, which could not be detected by traditional methods such as HRV analysis. By using PFR analysis, it is possible to make MGs without unpleasant sensations for better sports performance.博士（医学）・乙第1306号・平成24年11月27日Copyright © 2012 Japanese Stomatological Society. Published by Elsevier Japan K

Establishment of a monoclonal antibody for human LXRα: Detection of LXRα protein expression in human macrophages

Liver X activated receptor alpha (LXRα) forms a functional dimeric nuclear receptor with RXR that regulates the metabolism of several important lipids, including cholesterol and bile acids. As compared with RXR, the LXRα protein level in the cell is low and the LXRα protein itself is very hard to detect. We have previously reported that the mRNA for LXRα is highly expressed in human cultured macrophages. In order to confirm the presence of the LXRα protein in the human macrophage, we have established a monoclonal antibody against LXRα, K-8607. The binding of mAb K-8607 to the human LXRα protein was confirmed by a wide variety of different techniques, including immunoblotting, immunohistochemistry, and electrophoretic mobility shift assay (EMSA). By immunoblotting with this antibody, the presence of native LXR protein in primary cultured human macrophage was demonstrated, as was its absence in human monocytes. This monoclonal anti-LXRα antibody should prove to be a useful tool in the analysis of the human LXRα protein

Pullout Strength of Pedicle Screws

Study Design: A cadaveric biomechanical study designed to test the pullout strength of pedicle screws. Objective: To evaluate the pullout strength of redirected pedicle screws with a larger diameter following lateral wall breach, redirected pedicle screws of the same diameter following medial wall breach, and redirected pedicle screws with a larger diameter following medial wall breach. Summary of Background Data: Screw malposition is one of the main pitfalls of inserting pedicle screws. Intraoperatively a malpositioned screw is re-directed and inserted along the correct axis. Methods: Forty-seven vertebrae (T9–L5) were harvested from 8 fresh cadaveric spines. The 18 pedicle screws that breached the lateral wall were then removed and redirected using a pedicle screw of 1 mm larger in diameter. The 16 pedicle screws that had breached the medial wall were then removed and redirected using a pedicle screw of the same diameter. The other 13 pedicle screws that had breached the medial wall were then removed and redirected using a pedicle screw of 1 mm larger in diameter. The pullout strength was measured. Results: Following lateral wall breach, mean pullout strength for the larger redirected screws was 46.9% greater than that of the correctly aligned screws. Following medial wall breach, mean pullout strength for the redirected screws of the same diameter was 20.6% less than that of the correctly aligned screws. Mean pullout strength for the larger pedicle screws following medial wall breach was 27.3% more than that of the correctly aligned screws. Conclusion: Redirected pedicle screws of larger diameter after a lateral or medial pedicle breach show recovery of pullout strength. However, the pullout strength of redirected pedicle screws of the same diameter after a medial pedicle breach is significantly less than that of correctly aligned screws.Redirected pedicle screws of larger diameter after a lateral or medial pedicle breach show the recovery of pullout strength. However, the pullout strength of redirected pedicle screws of the same diameter after a medial pedicle breach is significantly less than that of correctly aligned screws

Comparing ChromeOS and Microsoft Windows for Writing Documents

コンピューターはOS を基盤として動作し、この違いは操作の違いに繋がっている。本研究では、Windows に慣れていれるもののChromeOS を使用したことが無い利用者が、ChromeOS を習得するために必要な使用回数を調査する。本研究では特に文書作成に着目した。調査の方法は、Windows とChromeOS の両方を協力者に使用してもらい、文書作成の時間、コンピューターの操作時間、及び、満足感を比較した。その結果、ChromeOSでの文書作成は４回程度の使用で習得できる可能性がある。さらに、コンピューターの基本的な操作については、１回程度の使用で習得できる可能性が示唆された。なお、文書作成のために特別な講習や指導は必要としなかった。また、文書作成アプリは、Windows ではMicrosoft Word、ChromeOS ではGoogle ドキュメントを使用した。最後に、文書作成の速度はChromeOS よりWindows の方が速かった。そして、Windows と同等の速度に至るためには、OS と文書作成アプリの操作に慣れるだけなく、予測変換を使いこなす必要がある。journal articl