发现大肠埃希菌喹诺酮耐药株gyrA基因新亚型和aac（6′）-Ⅰ b-Cr、mdfA基因

目的 了解大肠埃希菌(E.coli)对常用抗菌药物的耐药性及喹诺酮类DNA旋转酶基因、多药外排基因及氨基糖苷类修饰酶基因（AMEs）的存在情况。 方法 收集2006年1月~2008年10月本院临床标本分离的E.coli 60株,用K-B法检测细菌对16种抗菌药物的敏感性,用PCR及测序技术分析6种喹诺酮类基因(gyrA、qnrA、qnrB、qnrS、qepA、mdfA)和1种AMEs基因aac(6′)-Ⅰ b。 结果 60株菌对环丙沙星和左氧氟沙星的耐药率均为78.4%（47/60）;55株菌存在gyrA基因突变,其中3株菌gyrA与美国NCBI中已登录的gyrA基因序列不同,为新亚型;mdfA基因均阳性;对9株aac(6′)-Ⅰ b基因PCR阳性产物进行测序,证实5株携带aac（6′）-Ⅰ b-Cr双功能酶基因。 结论 gyrA基因突变是E.coli对喹诺酮类药物最主要的耐药机制,耐喹诺酮类药物的E.coli株中发现aac（6′）-Ⅰ b-Cr基因和gyrA新亚型,E.coli检出mdfA基因为中国大陆地区首次报道。     

Does the Feldenkrais Method make a difference? An investigation into the use of outcome measurement tools for evaluating changes in clients

Evidence-based practice confirms the need for outcome measures. Feldenkrais Method practitioners struggle to use such tools because of the broad range of applications of the Feldenkrais Method and the difficulty identifying suitable measurement tools. A pre/post-test design was used to investigate the use of three outcome measurement tools [Patient-specific Functional Scale (PSFS), Pain Outcome Profile (POP) and Short Form12v2 Health questionnaire (SF12v2)] for clients experiencing problems performing everyday functional tasks who attended Feldenkrais sessions. Eleven Feldenkrais practitioners submitted data on 48 clients. Changes were detected in the clients’ ability to perform everyday tasks (PSFS improved 3.8 points, p < 0.001), levels of pain decreased (POP improved in current pain p = 0.001, physical index p < 0.001 and affective index p = 0.001) and quality of life improved significantly in six of the eight SF12v2 domains. These three tools have been found to be suitable for detecting changes in client function before and after a series of Feldenkrais sessions.     

The effect of tranexamic acid on artificial joint materials: a biomechanical study (the bioTRANX study)

Background

Tranexamic acid (TXA) has been successfully used to reduce bleeding in joint replacement. Recently local TXA has been advocated to reduce blood loss in total knee or hip replacement; however, this raised concerns about potential adverse effects of TXA upon the artificial joint replacement.

Materials and methods

In this biomechanical study we compared the effects of TXA and saline upon the following biomechanical properties of artificial joint materials—(1) tensile properties (ultimate strength, stiffness and Young’s modulus), (2) the wear rate using a multi-directional pin-on-plate machine, and (3) the surface topography of pins and plates before and after wear rate testing.

Results

There were no significant differences in tensile strength, wear rates or surface topography of either ultra-high-molecular-weight polyethylene pins or cobalt chromium molybdenum metal plates between specimens soaked in TXA and specimens soaked in saline.

Conclusion

Biomechanical testing shows that there are no biomechanical adverse affects on the properties of common artificial joint materials from using topical TXA.

Level of evidence

V     

Dual contrast in computed tomography allows earlier characterization of articular cartilage over single contrast

Cationic computed tomography contrast agents are more sensitive for detecting cartilage degeneration than anionic or non-ionic agents. However, osteoarthritis-related loss of proteoglycans and increase in water content contrarily affect the diffusion of cationic contrast agents, limiting their sensitivity. The quantitative dual-energy computed tomography technique allows the simultaneous determination of the partitions of iodine-based cationic (CA4+) and gadolinium-based non-ionic (gadoteridol) agents in cartilage at diffusion equilibrium. Normalizing the cationic agent partition at diffusion equilibrium with that of the non-ionic agent improves diagnostic sensitivity. We hypothesize that this sensitivity improvement is also prominent during early diffusion time points and that the technique is applicable during contrast agent diffusion. To investigate the validity of this hypothesis, osteochondral plugs (d = 8 mm, N = 33), extracted from human cadaver (n = 4) knee joints, were immersed in a contrast agent bath (a mixture of CA4+ and gadoteridol) and imaged using the technique at multiple time points until diffusion equilibrium. Biomechanical testing and histological analysis were conducted for reference. Quantitative dual-energy computed tomography technique enabled earlier determination of cartilage proteoglycan content over single contrast. The correlation coefficient between human articular cartilage proteoglycan content and CA4+ partition increased with the contrast agent diffusion time. Gadoteridol normalized CA4+ partition correlated significantly (P < .05) with Mankin score at all time points and with proteoglycan content after 4 hours. The technique is applicable during diffusion, and normalization with gadoteridol partition improves the sensitivity of the CA4+ contrast agent.