Attentional selectivity,automaticity, and self-efficacy predict simulator-acquired skill transfer to the clinical environment

Introduction

Several studies demonstrated that simulator-acquired skill transfer to the operating room is incomplete. Our objective was to identify trainee characteristics that predict the transfer of simulator-acquired skill to the operating room.

Frontotemporal dementia and parkinsonism linked to chromosome 17 with the N279K tau mutation

We present a case of frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP‐17) harboring the N279K mutation in the MAPT gene from the family known as pallido‐ponto‐nigral degeneration (PPND). This 49‐year‐old man was followed for 17 years. He presented at age 41 years with left leg stiffness and en‐bloc turning. During the course of his illness he developed a constellation of symptoms including parkinsonism, pyramidal signs, vertical gaze palsy, dysphagia, dystonia, personality and cognitive dysfunction, weight loss and mutism. Gross neuropathological examination showed mild atrophy of the cerebral cortex, hippocampal formation, amygdala, thalamus, subthalamic nucleus and depigmentation of the substantia nigra. Microscopy revealed neuronal loss and gliosis in the same regions. Tau immunohistochemistry showed pretangles, numerous threads, grain‐like structures and oligodendroglial tau‐positive inclusions (“coiled bodies”). In the spinal cord the tau pathology was more abundant in gray than white matter. Pretangles and threads were present in the anterior and, to a lesser extent, in the posterior horns. FTDP‐17 should be suspected in patients with a history of familial parkinsonism combined with behavioral and cognitive changes, onset before age 65 years and an aggressive clinical course.     

The MRC OX-22- CD4+ T cells that help B cells in secondary immune responses derive from naive precursors with the MRC OX-22+ CD4+ phenotype

CD4+ T cells in the rat can be divided into two nonoverlapping subsets by their reactivity with the mAb MRC OX-22, which binds some of the high molecular weight forms of the CD45 antigen. The lineage relationship between subsets of CD4+ T cells expression different forms of CD45 has been a controversial issue for some time. Experiments described in this paper address this question using in vivo assays of T cell reactivity. Analysis of primary antibody responses in vivo show that it is MRC OX-22+ CD4+ T cells that are active in these assays, whereas antigen-primed T cells that provide helper activity for secondary antibody responses in vivo have the MRC OX-22- CD4+ phenotype. It is demonstrated that these memory T cells derive from MRC OX-22+ CD4+ T cell precursors and not from a putative separate lineage. It is concluded that with respect to the provision of help for B cells, MRC OX-22+ CD4+ T cells are precursors of memory cells with the phenotype MRC OX-22- CD4+.     

THE MEASUREMENT OF SOCIOECONOMIC INEQUALITY AND SOCIAL CLASS IN AUSTRALIA: A REVIEW OF PAST PRACTICES AND RECENT DEVELOPMENTS

Recent findings have pointed to an association between socioeconomic status and health in Australia but have, in the process, raised important questions about the validity of various methods of determining a respondent's location within the hierarchy. While some of the problems associated with the use of the Australian Bureau of Statistics classification were known, the full extent of these deficiencies was not. This paper reviews past and present methods of measuring socioeconomic inequality in Australia. After pointing to the criteria which should be applied to determine the adequacy of any method of socioeconomic classification, the paper reviews the main strengths and weaknesses of the methods of classification used in health-related research in Australia.     

Limitations of a convolution method for modeling geometric uncertainties in radiation therapy: the radiobiological dose-per-fraction effect

The convolution method can be used to model the effect of random geometric uncertainties into planned dose distributions used in radiation treatment planning. This is effectively done by linearly adding infinitesimally small doses, each with a particular geometric offset, over an assumed infinite number of fractions. However, this process inherently ignores the radiobiological dose-per-fraction effect since only the summed physical dose distribution is generated. The resultant potential error on predicted radiobiological outcome [quantified in this work with tumor control probability (TCP), equivalent uniform dose (EUD), normal tissue complication probability (NTCP), and generalized equivalent uniform dose (gEUD)] has yet to be thoroughly quantified. In this work, the results of a Monte Carlo simulation of geometric displacements are compared to those of the convolution method for random geometric uncertainties of 0, 1, 2, 3, 4, and 5 mm (standard deviation). The alpha/betaCTV ratios of 0.8, 1.5, 3, 5, and 10 Gy are used to represent the range of radiation responses for different tumors, whereas a single alpha/betaOAR ratio of 3 Gy is used to represent all the organs at risk (OAR). The analysis is performed on a four-field prostate treatment plan of 18 MV x rays. The fraction numbers are varied from 1-50, with isoeffective adjustments of the corresponding dose-per-fractions to maintain a constant tumor control, using the linear-quadratic cell survival model. The average differences in TCP and EUD of the target, and in NTCP and gEUD of the OAR calculated from the convolution and Monte Carlo methods reduced asymptotically as the total fraction number increased, with the differences reaching negligible levels beyond the treatment fraction number of > or =20. The convolution method generally overestimates the radiobiological indices, as compared to the Monte Carlo method, for the target volume, and underestimates those for the OAR. These effects are interconnected and attributed to assuming an infinite number of fractions inherent in the implementation of the convolution technique, irrespective of the uniqueness of each treatment schedule. Based on the fraction numbers analyzed (1-50), and the range of fraction numbers normally used clinically (> or =20), the convolution method can be used safely to estimate the effects of random geometric uncertainties on prostate treatment radiobiological outcomes, for both the target and the OAR. Although the results of this study is likely to apply to other clinical sites and treatment techniques other than the four-field, further validation similar to those done in this study may be necessary prior to clinical implementation.     

CTLA-4 expression on antigen-specific cells but not IL-10 secretion is required for oral tolerance

CD4(+) T cells play a vital role in mediating the tolerance induced at mucosal sites following exposure to non-pathogenic stimuli, and further understanding of the precise mechanisms by which these cells prevent aberrant responses is required. We have developed a model using transfer of DO11.10 TCR-transgenic bone marrow into irradiated recipients in which it has been possible to track antigen-specific CD4(+) cells in mesenteric lymph nodes (mLN), Peyer's patches (PP) and lamina propria following primary exposure to antigen. Using this model we have demonstrated initial activation in all three gut-associated lymphoid tissue compartments characterized by increases in the frequency of transgenic cells expressing CD69 and CD25. These cells subsequently enter a state of hyporesponsiveness both locally in the mLN and PP and in the periphery following feeding and challenge. Investigating the role of CTLA-4 either using anti-CTLA-4 mAb or by generating chimeras using DO11.10xCTLA-4(-/-) mice as donors we have clearly shown that antigen-specific cells require the expression of this regulatory molecule for oral tolerance. In contrast, oral tolerance was intact in chimeras generated using DO11.10xIL-10(-/-) cells, indicating that secretion of this cytokine by antigen-specific cells is not required.     

Phenotypically distinct subsets of CD4+ T cells induce or protect from chronic intestinal inflammation in C. B-17 scid mice

CD4⁺ T cells in the mouse can be subdivided into two fractionsbased on the level of expression of the CD45RB determinant.Previous studies have shown that these subsets are functionallydistinct. We have further characterized the properties of thesesubpopulations in vivo by injecting them into C. B-17 scid mice.The animals restored with the CD45RB^highCD4⁺ T cell populationdeveloped a lethal wasting disease with severe mononuclear cellinfiltrates into the colon and elevated levels of IFN- mRNA.In contrast, animals restored with the reciprocal CD45RB^lowsubset or with unfractionated CD4⁺ T cells did not develop thewasting or colitis. Importantly, the co-transfer of the CD45RB^lowpopulation with the CD45RB^high population prevented the wastingdisease and colitis. These data indicate that important regulatoryinteractions occur between the CD45RB^high and CD45RB^lowCD4⁺T cell subsets and that disruption of this mechanism has fatalconsequences.     

Complication Rates Following Total Ankle Arthroplasty in Inpatient versus Outpatient Populations: A Systematic Review & Meta-Analysis

Total ankle arthroplasty (TAA) is used as an alternative to ankle arthrodesis for adults with severe ankle arthritis. Numerous orthopedic centers have entered the healthcare market offering fast-tracked joint replacement protocols, meanwhile, TAA has been excluded from these joint centers, and is primarily performed in the inpatient setting. The purpose of this study is to examine short-term complications in the inpatient and outpatient settings following TAA using a systematic review and quantitative analysis. We considered all studies examining short-term complications following TAA performed in the inpatient versus outpatient setting occuring within 1 year of the index operation. We summarized data using a pooled relative risk and random effects model. A pooled sensitivity analysis was performed for studies with data on complication rates for inpatient or outpatient populations, which did not have a control group. The quality of included studies was assessed using the Cochrane risk of bias tool. Nine studies were included in the quantitative analysis, with 4 studies in the final meta-analysis. Subjects undergoing inpatient surgery experienced a 5-times higher risk of short-term complications compared to the outpatient group (risk ratio 5.27, 95% confidence interval 3.31, 8.42). Results did not change after sensitivity analysis (inpatient weighted mean complication rate: 9.62% vs outpatient weighted mean 5.02%, p value <.001). The overall level of evidence of included studies was level III, with a moderate to high risk of bias. Outpatient TAAs do not appear to pose excess complication risks compared to inpatient procedures, and may therefore be a reasonable addition to experienced centers that have established a fast-track outpatient total joint protocol.