Predicting knee cartilage loss using adaptive partitioning of cartilage thickness maps

This study investigates whether measures of knee cartilage thickness can predict future loss of knee cartilage. A slow and a rapid progressor group was determined using longitudinal data, and anatomically aligned cartilage thickness maps were extracted from MRI at baseline. A novel machine learning framework was then trained using these maps. Compared to measures of mean cartilage plate thickness, group separation was increased by focusing on local cartilage differences. This result is central for clinical trials where inclusion of rapid progressors may help reduce the period needed to study effects of new disease-modifying drugs for osteoarthritis.     

膝关节镜引导小切口手术对胫骨平台骨折患者HSS评分及并发症发生率的影响研究

目的探索膝关节镜引导小切口手术与传统切开复位内固定术治疗胫骨平台骨折患者的术后康复情况及临床效果。方法87例胫骨平台骨折患者,依据采取的手术方法不同分为实验组(44例)和对照组(43例)。实验组患者采用膝关节镜引导小切口手术方案治疗,对照组患者采取传统切开复位内固定手术方案治疗。比较两组患者的术中失血量、下床活动时间、术后引流量、膝关节功能量表(HSS)评分及并发症发生率。结果实验组患者术中失血量(47.40±8.64)ml、术后引流量(37.53±4.36)ml少于对照组的(55.37±10.32)、(45.63±5.64)ml,下床活动时间(4.05±1.22)d短于对照组的(6.71±2.33)d,差异有统计学意义(P<0.05)。手术后3、6个月,两组患者的HSS评分均高于手术前,且实验组高于对照组,差异有统计学意义(P<0.05)。实验组患者术后并发症发生率为4.55%(2/44),低于对照组的34.88%(15/43),差异具有统计学意义(P<0.05)。结论采用膝关节镜引导小切口手术治疗胫骨平台骨折的效果确切,对比患者术后的康复情况、HSS评分及并发症发生率等方面有明显的优势。     

NADPH oxidase activity controls phagosomal proteolysis in macrophages through modulation of the lumenal redox environment of phagosomes

The phagosomal lumen in macrophages is the site of numerous interacting chemistries that mediate microbial killing, macromolecular degradation, and antigen processing. Using a non-hypothesis-based screen to explore the interconnectivity of phagosomal functions, we found that NADPH oxidase (NOX2) negatively regulates levels of proteolysis within the maturing phagosome of macrophages. Unlike the NOX2 mechanism of proteolytic control reported in dendritic cells, this phenomenon in macrophages is independent of changes to lumenal pH and is also independent of hydrolase delivery to the phagosome. We found that NOX2 mediates the inhibition of phagosomal proteolysis in macrophages through reversible oxidative inactivation of local cysteine cathepsins. We also show that NOX2 activity significantly compromises the phagosome''s ability to reduce disulfides. These findings indicate that NOX2 oxidatively inactivates cysteine cathepsins through sustained ablation of the reductive capacity of the phagosomal lumen. This constitutes a unique mechanism of spatiotemporal control of phagosomal chemistries through the modulation of the local redox environment. In addition, this work further implicates the microbicidal effector NOX2 as a global modulator of phagosomal physiologies, particularly of those pertinent to antigen processing.     

Demarginalizing the marginalized in substance abuse treatment: Stories of homeless,active substance users in an urban harm reduction based drop-in center

This article reports stories of demarginalization in treatment as told by participants of a nonabstinence-based treatment program based on a harm reduction model targeting homeless active users. The stories told are ones where drug users–marginalized due to their drug and/or alcohol use–experienced the treatment setting in a destigmatizing, normalizing, humanizing and nonjudgmental manner. The purpose of this article is to describe the sense of demarginalization that participants experienced and to posit that demarginalization is a critical component in engaging “hard-to-reach” populations in substance abuse treatment. It assumes that listening to consumer voices about what is/is not meaningful to them in treatment can reveal much about program uptake or disconnect.     

Animal evolution,bioturbation, and the sulfate concentration of the oceans

As recognized already by Charles Darwin, animals are geobiological agents. Darwin observed that worms aerate and mix soils on a massive scale, aiding in the decomposition of soil organic matter. A similar statement can be made about marine benthic animals. This mixing, also known as bioturbation, not only aides in the decomposition of sedimentary organic material, but as contended here, it has also significantly influenced the chemistry of seawater. In particular, it is proposed that sediment mixing by bioturbating organisms resulted in a severalfold increase in seawater sulfate concentration. For this reason, the evolution of bioturbation is linked to the significant deposition of sulfate evaporate minerals, which is largely a phenomena of the Phanerozoic, the last 542 million years and the time over which animals rose to prominence.     

会师牵引加骨盆复位治疗后尿道断裂30例

目的：探讨骨盆骨折后尿道断裂的理想治疗方法。方法：对采用尿道会师牵引加骨盆复位治疗的30例骨盆骨折后尿道断裂患者的临床资料进行分析。结果：25例短期预防性尿道扩张后排尿满意，2例需定期尿道扩张，3例尿道狭窄后行尿道端端吻合治愈，并发阳痿2例。结论：本法操作简单、创伤小、并发症少，是治疗骨盆骨折后尿道断裂较为合理、有效的方法。     

Reactivity of capillaries and pyramidal neurons in rat cortex under conditions of acutely reduced circulation

A study of capillaries and pyramidal neurons of the cortex in white rats subjected to ligation of the common carotid artery reveals that acute reduction of the circulation is characterized by a decreased activity of alkaline phosphatase and Na, K-ATPase as well as a reduced number of capillaries marked with these enzymes, and a lower activity of butyrylcholine esterase. A decreased activity of cytochrome oxidase in neurons suggests the existence of intracellular compensatory-adaptive mechanisms. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 5, pp. 558–560, May, 1994 Presented by O. S. Adrianov, Member of the Russian Academy of Medical Sciences     

Interaction Between Polyalkylcyanoacrylate Nanoparticles and Peritoneal Macrophages: MTT Metabolism,NET Reduction,and NO Production

Purpose. The nature of interactions between macrophages and drug carriers is of primordial importance either in the design of more effective therapeutic strategies for macrophage-associated pathogenesis or in establishing new approaches for pharmacological action avoiding macrophages. Methods. Polyalkylcyanoacrylate nanoparticles (PMCA, PECA, PBCA and PIBCA nanoparticles) were assayed for their toxicity on peritoneal resident and thioglycolate-elicited macrophages. Cellular viability was assessed by MTT tetrazolium salt assay, oxidative burst by NBT reduction and NO production by nitrite evaluation. Results. The nanoparticles tested led to cellular morphological modifications and induced toxicity in both types of macrophages in culture. The polyalkylcyanoacrylate nanoparticles uptake by peritoneal macrophages caused an increase in respiratory burst, as assessed by the NBT reduction assay, and induced the release of soluble toxic factors to the culture medium. The association of LPS with the PMCA nanoparticles significantly stimulated the production of nitric oxide (NO) by resident macrophages. In contrast, the association of PBCA nanoparticles with LPS does not increase the nitrite production as compared with LPS alone, which may be due to a different physico-chemical interaction between LPS and the two types of polymers. Conclusions. In cultured mice peritoneal macrophages, nanoparticles of PACA induce the production of oxygen reactive products, which cause changes in the cell metabolism of both resident and elicited macrophages. PMCA nanoparticles in association with LPS significantly increase the expression of the inducible isoform of nitric oxide synthase, leading to the release of large amount of NO, which may be highly cytotoxic to the cultured cells in the presence of peroxide generated from the oxidative burst.     

Estimation with weak instruments: Accuracy of higher‐order bias and MSE approximations

Summary In this paper, we consider parameter estimation in a linear simultaneous equations model. It is well known that two‐stage least squares (2SLS) estimators may perform poorly when the instruments are weak. In this case 2SLS tends to suffer from the substantial small sample biases. It is also known that LIML and Nagar‐type estimators are less biased than 2SLS but suffer from large small sample variability. We construct a bias‐corrected version of 2SLS based on the Jackknife principle. Using higher‐order expansions we show that the MSE of our Jackknife 2SLS estimator is approximately the same as the MSE of the Nagar‐type estimator. We also compare the Jackknife 2SLS with an estimator suggested by Fuller (Econometrica 45, 933–54) that significantly decreases the small sample variability of LIML. Monte Carlo simulations show that even in relatively large samples the MSE of LIML and Nagar can be substantially larger than for Jackknife 2SLS. The Jackknife 2SLS estimator and Fuller's estimator give the best overall performance. Based on our Monte Carlo experiments we conduct informal statistical tests of the accuracy of approximate bias and MSE formulas. We find that higher‐order expansions traditionally used to rank LIML, 2SLS and other IV estimators are unreliable when identification of the model is weak. Overall, our results show that only estimators with well‐defined finite sample moments should be used when identification of the model is weak.     

急诊经皮撬拨复位克氏针内固定治疗SandersⅡ型跟骨骨折（附23例病例报告）

目的观察急诊经皮撬拨复位克氏针内固定治疗SandersⅡ型跟骨骨折的疗效,探讨SandersⅡ型跟骨骨折的治疗方案。方法选取2004年6月～2008年6月我院收治的23例跟骨骨折患者为研究对象,在X线监视下进行,采用经皮撬拨复位克氏针内固定治疗,术后以石膏管型外固定。结果所有患者获得12～36个月（平均19.5个月）随访。术后平均骨折愈合时间为10周。术后X线照片检查示Bhler角、Gissane角、跟骨外形基本恢复正常。结论急诊经皮撬拨复位克氏针内固定治疗SandersⅡ型跟骨骨折,具有操作简单、疗效可靠、创伤小、并发症少及恢复快等优点。