2,103 research outputs found
Radio-controlled model design and testing techniques for stall/spin evaluation of general-aviation aircraft
A relatively inexpensive radio-controlled model stall/spin test technique was developed. Operational experiences using the technique are presented. A discussion of model construction techniques, spin-recovery parachute system, data recording system, and movie camera tracking system is included. Also discussed are a method of measuring moments of inertia, scaling of engine thrust, cost and time required to conduct a program, and examples of the results obtained from the flight tests
Autistic Traits and Social Anxiety Predict Differential Performance on Social Cognitive Tasks in Typically Developing Young Adults
The current work examined the unique contribution that autistic traits and social anxiety have on tasks examining attention and emotion processing. In Study 1, 119 typically-developing college students completed a flanker task assessing the control of attention to target faces and away from distracting faces during emotion identification. In Study 2, 208 typically-developing college students performed a visual search task which required identification of whether a series of 8 or 16 emotional faces depicted the same or different emotions. Participants with more self-reported autistic traits performed more slowly on the flanker task in Study 1 than those with fewer autistic traits when stimuli depicted complex emotions. In Study 2, participants higher in social anxiety performed less accurately on trials showing all complex faces; participants with autistic traits showed no differences. These studies suggest that traits related to autism and to social anxiety differentially impact social cognitive processing
Altered gene expression and spongiotrophoblast differentiation in placenta from a mouse model of diabetes in pregnancy
Aims/hypothesis: Pregnancies complicated by diabetes have a higher risk of adverse outcomes for mothers and children, including predisposition to disease later in life, e.g. metabolic syndrome and hypertension. We hypothesised that adverse outcomes from diabetic pregnancies may be linked to compromised placental function, and sought to identify cellular and molecular abnormalities in diabetic placenta. Methods: Using a mouse model of diabetic pregnancy, placental gene expression was assayed at mid-gestation and cellular composition analysed at various stages. Genome-wide expression profiling was validated by quantitative PCR and tissue localisation studies were performed to identify cellular correlates of altered gene expression in diabetic placenta. Results: We detected significantly altered gene expression in diabetic placenta for genes expressed in the maternal and those expressed in the embryonic compartments. We also found altered cellular composition of the decidual compartment. In addition, the junctional and labyrinth layers were reduced in diabetic placenta, accompanied by aberrant differentiation of spongiotrophoblast cells. Conclusions/interpretation: Diabetes during pregnancy alters transcriptional profiles in the murine placenta, affecting cells of embryonic and maternal origin, and involving several genes not previously implicated in diabetic pregnancies. The molecular changes and abnormal differentiation of multiple cell types precede impaired growth of junctional zone and labyrinth, and of placenta overall. Regardless of whether these changes represent direct responses to hyperglycaemia or are physiological adaptations, they are likely to play a role in pregnancy complications and outcomes, and to have implications for developmental origins of adult disease. © 2011 Springer-Verlag
Comparison of two mechanical disaggregation methods of fresh lung tissues for extraction of high-quality RNA
Gene expression studies are widely used in medical, biological, and pharmaceutical research. Obtaining high-quality RNA from tissues is a prerequisite for high-quality data that should accurately represent gene expression levels in-vivo. The main source of technical bias, which could affect the results from transcriptomic studies, is variation in RNA quality. In this regard, tissue preparation is critical: different disruption techniques can affect RNA quality, influencing further applications. Mechanical disaggregation is a common, inexpensive, and simple method to obtain a high cell yield, demonstrated to efficiently disrupt the extracellular matrix and release single cells. However, its efficacy is operator-dependent, leading to poorly reproducible results. A fast, reproducible, and standardized technique could undoubtedly overcome this problem, avoiding wasting time and resources. In this study, our goal was to evaluate the impact of two mechanical tissue disruption techniques on the purity and quality of RNA extracted from fresh lung biopsies. The samples were processed in parallel using manual mechanical disaggregation or an automated mechanical device. The results showed that samples processed with the automated device had a higher integrity compared to those processed manually with a median Fragmentation Index of 0.86 and 0.71 respectively. This difference is statistically significant (p = 0.0084). Overall, our results indicated that the use of automatic mechanical disaggregation could undoubtedly help to overcome the technical biases related to fresh tissues processing
Effects of mesenchymal stromal cells versus serum on tendon healing in a controlled experimental trial in an equine model
Abstract Background Mesenchymal stromal cells (MSC) have shown promising results in the treatment of tendinopathy in equine medicine, making this therapeutic approach seem favorable for translation to human medicine. Having demonstrated that MSC engraft within the tendon lesions after local injection in an equine model, we hypothesized that they would improve tendon healing superior to serum injection alone. Methods Quadrilateral tendon lesions were induced in six horses by mechanical tissue disruption combined with collagenase application 3 weeks before treatment. Adipose-derived MSC suspended in serum or serum alone were then injected intralesionally. Clinical examinations, ultrasound and magnetic resonance imaging were performed over 24 weeks. Tendon biopsies for histological assessment were taken from the hindlimbs 3 weeks after treatment. Horses were sacrificed after 24 weeks and forelimb tendons were subjected to macroscopic and histological examination as well as analysis of musculoskeletal marker expression. Results Tendons injected with MSC showed a transient increase in inflammation and lesion size, as indicated by clinical and imaging parameters between week 3 and 6 (p < 0.05). Thereafter, symptoms decreased in both groups and, except that in MSC-treated tendons, mean lesion signal intensity as seen in T2w magnetic resonance imaging and cellularity as seen in the histology (p < 0.05) were lower, no major differences could be found at week 24. Conclusions These data suggest that MSC have influenced the inflammatory reaction in a way not described in tendinopathy studies before. However, at the endpoint of the current study, 24 weeks after treatment, no distinct improvement was observed in MSC-treated tendons compared to the serum-injected controls. Future studies are necessary to elucidate whether and under which conditions MSC are beneficial for tendon healing before translation into human medicine
Outcomes of Esophageal Dilation in Eosinophilic Esophagitis: Safety, Efficacy and Persistence of the Fibrostenotic Phenotype
Esophageal dilation is commonly performed in eosinophilic esophagitis (EoE), but there are few long-term data. The aims of this study were to assess the safety and long-term efficacy of esophageal dilation in a large cohort of EoE cases and determine the frequency and predictors of requiring multiple dilations
Hepatic autophagy contributes to the metabolic response to dietary protein restriction
© 2016 Elsevier Inc. All rights reserved. Autophagy is an essential cellular response which acts to release stored cellular substrates during nutrient restriction, and particularly plays a key role in the cellular response to amino acid restriction. However, there has been limited work testing whether the induction of autophagy is required for adaptive metabolic responses to dietary protein restriction in the whole animal. Here, we found that moderate dietary protein restriction led to a series of metabolic changes in rats, including increases in food intake and energy expenditure, the downregulation of hepatic fatty acid synthesis gene expression and reduced markers of hepatic mitochondrial number. Importantly, these effects were also associated with an induction of hepatic autophagy. To determine if the induction of autophagy contributes to these metabolic effects, we tested the metabolic response to dietary protein restriction in BCL2-AAA mice, which bear a genetic mutation that impairs autophagy induction. Interestingly, BCL2-AAA mice exhibit exaggerated responses in terms of both food intake and energy expenditure, whereas the effects of protein restriction on hepatic metabolism were significantly blunted. These data demonstrate that restriction of dietary protein is sufficient to trigger hepatic autophagy, and that disruption of autophagy significantly alters both hepatic and whole animal metabolic response to dietary protein restriction
The extremely narrow-caliber esophagus is a treatment-resistant subphenotype of eosinophilic esophagitis
Some patients with eosinophilic esophagitis (EoE) have an extremely narrowed esophagus, but the characteristics of this group have not been extensively described. We aimed to characterize the narrow-caliber phenotype of EoE, determine associated risk factors, and identify differences in treatment response in this sub-group of patients
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