Application of MORSE to radiation analysis of nuclear flight propulsion modules

Several modifications and additions were made to the multigroup Monte Carlo code (MORSE) to implement its use in a computational procedure for performing radiation analyses of NERVA nuclear flight propulsion modules. These changes include the incorporation of a new general geometry module; the inclusion of an expectation tracklength estimator; and the option to obtain source information from two-dimensional discrete ordinates calculations. Computations comparing MORSE and a point cross section Monte Carlo code, COHORT, were made in which a coupled discrete ordinates/Monte Carlo procedure was used to calculate the gamma dose rate at tank top locations of a typical propulsion module. The dose rates obtained from the MORSE computation agreed with the dose rates obtained from the COHORT computation to within the limits of the statistical accuracy of the calculations

Constructivism in Action: A Dynamic Group Process in Defining and Applying Principles of Social Justice

As a part of a Multicultural course, students in a doctoral program at a university in the Southwest worked together to synthesize a definition of social justice. The constructivist process implemented in this educational experience represented social justice in action, through co-construction of shared meaning. This definition, centered on Iris Young’s (2004) Five Faces of Oppression, resulted in the following: Social justice is addressing oppression, violence, exploitation, marginalization, powerlessness, and cultural imperialism through counselors’ efforts and advocacy, while promoting a critical perspective of the culture of silence. Social Justice is an active, effective change on micro- and macro-levels to alter social systems and institutions, whereby improving human rights and access to resources. Social justice is actively engaging in education, advocacy, critical thinking, systemic change, and client empowerment in order to diffuse mechanisms of oppression for the purpose of assisting clients in reaching their human potential

Regulation of cell survival by sphingosine-1-phosphate receptor S1P1 via reciprocal ERK-dependent suppression of bim and PI-3-kinase/protein kinase C-mediated upregulation of Mcl-1

Although the ability of bioactive lipid sphingosine-1-phosphate (S1P) to positively regulate anti-apoptotic/pro-survival responses by binding to S1P1 is well known, the molecular mechanisms remain unclear. Here we demonstrate that expression of S1P1 renders CCL39 lung fibroblasts resistant to apoptosis following growth factor withdrawal. Resistance to apoptosis was associated with attenuated accumulation of pro-apoptotic BH3-only protein Bim. However, although blockade of extracellular signal-regulated kinase (ERK) activation could reverse S1P1-mediated suppression of Bim accumulation, inhibition of caspase-3 cleavage was unaffected. Instead S1P1-mediated inhibition of caspase-3 cleavage was reversed by inhibition of phosphatidylinositol-3-kinase (PI3K) and protein kinase C (PKC), which had no effect on S1P1 regulation of Bim. However, S1P1 suppression of caspase-3 was associated with increased expression of anti-apoptotic protein Mcl-1, the expression of which was also reduced by inhibition of PI3K and PKC. A role for the induction of Mcl-1 in regulating endogenous S1P receptor-dependent pro-survival responses in human umbilical vein endothelial cells was confirmed using S1P receptor agonist FTY720-phosphate (FTY720P). FTY720P induced a transient accumulation of Mcl-1 that was associated with a delayed onset of caspase-3 cleavage following growth factor withdrawal, whereas Mcl-1 knockdown was sufficient to enhance caspase-3 cleavage even in the presence of FTY720P. Consistent with a pro-survival role of S1P1 in disease, analysis of tissue microarrays from ER+ breast cancer patients revealed a significant correlation between S1P1 expression and tumour cell survival. In these tumours, S1P1 expression and cancer cell survival were correlated with increased activation of ERK, but not the PI3K/PKB pathway. In summary, pro-survival/anti-apoptotic signalling from S1P1 is intimately linked to its ability to promote the accumulation of pro-survival protein Mcl-1 and downregulation of pro-apoptotic BH3-only protein Bim via distinct signalling pathways. However, the functional importance of each pathway is dependent on the specific cellular context

Preoperative statin treatment is associated with reduced postoperative mortality and morbidity in patients undergoing cardiac surgery: An 8-year retrospective cohort study

BackgroundCardiac surgical procedures can be associated with significant morbidity and mortality. Recently, it has been recognized that statins might induce multiple biologic effects independent of lipid lowering that could potentially ameliorate adverse surgical outcomes. Accordingly, this study tested the central hypothesis that pretreatment with statins before cardiac surgery would reduce adverse postoperative surgical outcomes.MethodsDemographic and outcomes data were collected retrospectively for 3829 patients admitted for planned cardiac surgery between February 1994 and December 2002. Statin pretreatment occurred in 1044 patients who were comparable with non–statin-pretreated (n = 2785) patients with regard to sex, race, and age. Primary outcomes examined included postoperative mortality (30-day) and a composite morbidity variable.ResultsThe odds of experiencing 30-day mortality and morbidity were significantly less in the statin-pretreated group, with unadjusted odds ratios of 0.43 (95% confidence interval [CI], 0.28-0.66) and 0.72 (95% CI, 0.61-0.86), respectively. Risk-adjusted odds ratios for mortality and morbidity were 0.55 (95% CI, 0.32-0.93) and 0.76 (95% CI, 0.62-0.94), respectively, by using a logistic regression model and 0.51 (95% CI, 0.27-0.94) and 0.71 (95% CI, 0.55-0.92), respectively, in the propensity-matched model, demonstrating significant reductions in 30-day morbidity and mortality. In a subsample of patients undergoing valve-only surgery (n = 716), fewer valve-only patients treated with statins experienced mortality, although these results were not statistically significant (1.96% vs 7.5%).ConclusionsThese findings indicate that statin pretreatment before cardiac surgery confers a protective effect with respect to postoperative outcomes

Unique reporter-based sensor platforms to monitor signalling in cells

Introduction: In recent years much progress has been made in the development of tools for systems biology to study the levels of mRNA and protein, and their interactions within cells. However, few multiplexed methodologies are available to study cell signalling directly at the transcription factor level. <p/>Methods: Here we describe a sensitive, plasmid-based RNA reporter methodology to study transcription factor activation in mammalian cells, and apply this technology to profiling 60 transcription factors in parallel. The methodology uses two robust and easily accessible detection platforms; quantitative real-time PCR for quantitative analysis and DNA microarrays for parallel, higher throughput analysis. <p/>Findings: We test the specificity of the detection platforms with ten inducers and independently validate the transcription factor activation. <p/>Conclusions: We report a methodology for the multiplexed study of transcription factor activation in mammalian cells that is direct and not theoretically limited by the number of available reporters

Neck fracture of a cementless forged titanium alloy femoral stem following total hip arthroplasty: a case report and review of the literature

<p>Abstract</p> <p>Introduction</p> <p>Fractures of the neck of the femoral component have been reported in uncemented total hip replacements, however, to our knowledge, no fractures of the neck of a cementless forged titanium alloy femoral stem coated in the proximal third with hydroxy-apatite have been reported in the medical literature.</p> <p>Case presentation</p> <p>This case report describes a fracture of the neck of a cementless forged titanium alloy stem coated in the proximal third with hydroxy-apatite.</p> <p>Conclusion</p> <p>The neck of the femoral stem failed from fatigue probably because of a combination of factors described analytically below.</p

STepped exercise program for patients with knee OsteoArthritis (STEP-KOA): protocol for a randomized controlled trial

Background: Physical therapy (PT) and other exercise-based interventions are core components of care for knee osteoarthritis (OA), but both are underutilized, and some patients have limited access to PT services. This clinical trial is examining a STepped Exercise Program for patients with Knee OsteoArthritis (STEP-KOA). This model of care can help to tailor exercise-based interventions to patient needs and also conserve higher resource services (such as PT) for patients who do not make clinically relevant improvements after receiving less costly interventions. Methods / Design: Step-KOA is a randomized trial of 345 patients with symptomatic knee OA from two Department of Veterans Affairs sites. Participants are randomized to STEP-KOA and Arthritis Education (AE) Control groups with a 2:1 ratio, respectively. STEP-KOA begins with 3 months of access to an internet-based exercise program (Step 1). Participants not meeting response criteria for clinically meaningful improvement in pain and function after Step 1 progress to Step 2, which involves bi-weekly physical activity coaching calls for 3 months. Participants not meeting response criteria after Step 2 progress to in-person PT visits (Step 3). Outcomes will be assessed at baseline, 3, 6 and 9 months (primary outcome time point). The primary outcome is the Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC), and secondary outcomes are objective measures of physical function. Linear mixed models will compare outcomes between the STEP-KOA and AE control groups at follow-up. We will also evaluate patient characteristics associated with treatment response and conduct a cost-effectiveness analysis of STEP-KOA. Discussion: STEP-KOA is a novel, efficient and patient-centered approach to delivering exercise-based interventions to patients with knee OA, one of the most prevalent and disabling health conditions. This trial will provide information on the effectiveness of STEP-KOA as a novel potential model of care for treatment of OA

A New Digital Preoperative Planning Method for Total Hip Arthroplasties

Preoperative templating is an important part of a THA. The ability to accurately determine magnification of the hip on the radiograph and apply identical magnification to the radiograph and template will improve accuracy of preoperative templating of THA. We designed a templating method using a new way of determining the hip magnification with a linear relationship between magnification of the hip and the reference object on top of the pubis symphysis; the relationship was determined on 50 radiographs. We then compared our method with two other templating methods: an analog method assuming an average hip magnification of 15% and a digital method determining the hip magnification with a one-to-one relationship between the reference object and the hip. All methods were reproducible. Uniform undersizing occurred when templating with the digital method based on the one-to-one relationship; the analog method best predicted the implanted prosthesis size, closely followed by our new digital templating method; the new method will be particularly applicable for preoperative THA when analog methods are replaced by digital methods