Exploring the Production of Extracellular Matrix by Astrocytes in Response to Mimetic Traumatic Brain Injury

Following injury to the central nervous system, extracellular modulations are apparent at the site of injury, often resulting in a glial scar. Astrocytes are mechanosensitive cells, which can create a neuroinhibitory extracellular environment in response to injury. The aim for this research was to gain a fundamental understanding of the affects a diffuse traumatic brain injury has on the astrocyte extracellular environment after injury. To accomplish this, a bioreactor culturing astrocytes in 3D constructs delivered 150G decelerations with 20% biaxial strain to mimic a traumatic brain injury. Experiments were designed to compare the potential effects of media type, number of impacts, and impacts with or without strain. Multiple impacts on astrocytes resulted in increased apoptosis, supporting cumulative effects of multiple traumatic brain injury events. Surprisingly, the expression of glial fibrillary acidic protein and S100B by astrocytes was downregulated following injury. With multiple impacts, astrocytes downregulated collagen and glycosaminoglycan expression at acute time points. Suppression of matrix metalloproteinase-2 coupled with unchanging production of transforming growth factor beta-1 and tissue inhibitor of metalloproteinase-1 indicates an inability to degrade damaged ECM or produce new ECM. This was supported by long-term studies which indicate significant decreases in chondroitin sulfate proteoglycan and collagen I accumulation. This could suggest astrocytes experiencing damaging mechanical stimulation enter a survival state ceasing to moderate the extracellular environment at short time points after injury

Optimizing in vitro extracellular matrix production using polymer scaffolds with targeted pore size

Extracellular matrix (ECM) has been shown to provide the framework needed for healthy tissue to grow after experiencing an injury. The optimization of growing ECM is a pressing concern in the tissue regeneration field. From prior research, an in vitro approach for harvesting ECM has been created using polyurethane (PU) foams seeded with cells. Our approach aimed at discovering if the pore size of the foams increased the amount of recovered ECM. Scaffolds of targeted pore size were created by separating sugar granules using a sieve, packing the sugar into a cylindrical mold, then pouring PU over the sugar. Three groups were created: a control of all sugar granules, sugar granules sized 250-500um, and sugar granules sized 125-250um. Cells were seeded and grown for three weeks on the foams. After three weeks, the scaffolds were dissolved and the ECM was collected. The final yields of each scaffold type produced statistically insufficient results. The control scaffolds yielded 4.15 mg ECM , the 125-250um pore scaffold yielded 3.55mg, and the 250-500um pore scaffold yielded 3.82mg. Further, the overall structures of the ECM did not appear different for each group. The results of the study show the pore size of the scaffold does not effect the overall production of ECM. Sieving sugar for specific pore size appears to have a minimal effect and is not necessary in creating the scaffolds

Understanding pictures : a study in the design of appropriate visual materials for education in developing countries.

The human resources approach to national development has challenged educators to find ways of communicating with village people that do not rely on the written word. Pictures are being used increasingly as a way to deliver messages to illiterate groups. Recent cross-cultural research has shown, however, that many of the assumptions made about the kinds of information that can be delivered through pictures needs to be re-examined. Part I of the study sets forth the rationale for using pictures in nonformal educational settings and examines two current approaches to the problem of picture perception. The constructive theory maintains that pictures are inherently ambiguous and require active interpretation on the part of the viewer. The registration theory suggests that pictures give information which derives from the ecology of light. In this view, the recognition of graphic depictions is considered to be a fairly passive matter and a gift allowed to us by the environment. The evidence of cross-cultural research in picture perception which fives support to each of these positions is reviewed. Part I also discusses cross-cultural studies of intelligence and examines a body of literature which demonstrates that the intellectual demands of village life are often such that they do not stimulate some of the higher cognitive processes identified by Piaget. The author takes the position advanced by Piaget and Vygotsky that the development of conceptual awareness advances from an intuitive level to one of conscious understanding. Bruner\u27s thesis concerning three modes of learning is also discussed. The traditional modes of learning in village settings are enactive (learning by doing) and iconic (learning by modeling). Symbolic learning which is learning by being told, usually takes place out of the context of ongoing action and, as such, is a radical departure from traditional practice. Like written language, pictures provide a form of symbolically coded experience, and in many cases the learner must be consciously aware of the cures of pictorial expression and how they are used, in order to properly decode their meaning. Part II details an empirical study carried out in Nepal with four samples of adult subjects: villagers with no schooling, villagers wit some primary or secondary schooling, workers in a furniture factory in the capital city of Kathmandu, and students at Tribhuvan University\u27s Institute of Engineering. A series of sixteen experiments was carried out. The abilities tested were the recognition of depicted objects, the understanding of spatial relationships in concrete situations, and the comprehension of pictorial space. In an effort to avoid introducing arbitrary graphic conventions, photographs and line drawings based on photographs were primarily used as the pictorial stimuli. The recognition of familiar objects in pictures was found to be a great deal easier than the comprehension of pictorial space. The village samples showed a generally poor understanding of euclidian and projective relationships both with regard to real objects and in interpreting pictures. The furniture factory workers and the engineering students performed at higher levels on all experiments, showing that environmental influences or specific experiences of some kind are important both in the development of spatial abilities and in the understanding of pictorial space. On the other hand, topological relationships in pictures were easily grasped by almost all of the villagers. The author concludes that perspective information was understood at only an intuitive level by the majority of the villagers tested and could not be consciously applied to the interpretation of spatial relationships in pictures. Projective information was consistently interpreted topologically by most of the village subjects. The author suggests that the recognition of familiar objects in pictures is largely an ability which does not require special learning, but that the interpretation of pictorial space is an active process which calls for conscious awareness of projective principles . Recommendations for the design of visual materials for use in nonformal educational settings are made

The Effects of a Guided Imagery Intervention on the Working Memory of Primary Aged Students

Many practitioners view working memory as the temporary capacity to store and manipulate information. Current findings suggest a developmental trajectory of working memory and other executive functions. Limited research has been effective in improving working memory using short term methods; however, recent findings suggest guided imagery and mindfulness meditation improves working memory in children. This study examined whether or not a 30 day guided imagery intervention affected the working memory of students in the primary grades of an elementary school. Participants from a sample of convenience were randomly assigned to a guided imagery intervention (n = 12) or to a waitlist control group (n = 12) and received the intervention following the 30 day implementation. Pretest and post test data determined no interaction between the groups and pretest and posttest measures following interaction. Qualitative data from teacher reports note growth in the ability to complete tasks independently and following multistep directions. The study supports the feasibility of using a time limited guided imagery intervention with younger students during the school day to foster classroom climate and student mood. Study design elements hampered determining the impact of the guided imagery intervention on working memory and executive functioning. Additional studies may demonstrate these effects

A Qualitative Study of Mixed Level Student\u27s Attitudes towards Studying English Discursive Communication with the Use of an Instructional Blog Site.

This paper examines English students\u27 attitudes towards a web blog that was employed as an instructional tool in order to facilitate and build on study performed in the classroom. Following a selected overview of previous studies into the pedagogical benefits of web blogging, a description of the instructional aims of the researchers\u27 web blogs is outlined. The effectiveness of the research is then assessed with reference to data taken from student response questionnaire data. Recommendations made in light of this data suggest that future research could focus upon ways to improve the effectiveness and presentation of future course web blogs

Boner\u27s Ark

A negative photographic version of a comic strip featuring an Abraham Lincoln theme. Originally published in King Features Syndicate.https://scholarsjunction.msstate.edu/fvw-artifacts/2402/thumbnail.jp

Speaking with different voices: the problems with English law and psychiatric injury

Private law courts in the UK have maintained the de minimis threshold as a condition precedent for a successful claim for the infliction of mental harm. This de minimis threshold necessitates the presence of a ‘recognised psychiatric illness’ as opposed to ‘mere emotion’. This standard has also been adopted by the criminal law courts when reading the Offences Against the Person Act 1861 to include non-physical injury. In determining the cut-off point between psychiatric injury and mere emotion, the courts have adopted a generally passive acceptance of expert testimony and the guidelines used by mental health professionals to make diagnoses. Yet these guidelines were developed for use in a clinical setting, not a legal one. This article examines the difficulty inherent in utilising the ‘dimensional’ diagnostic criteria used by mental health professionals to answer ‘categorical’ legal questions. This is of particular concern following publication of the new diagnostic manual, DSM-V in 2013, which will further exacerbate concerns about compatibility. It is argued that a new set of diagnostic guidelines, tailored specifically for use in a legal context, is now a necessity

Engineering of extracellular matrix scaffolds via hollow fiber cell culture

Extracellular matrix (ECM) tissue scaffolds are seeing increased use for clinical applications, as they significantly decrease the time course of healing for injured tissues; however, the use of animal-sourced matrix for these scaffolds introduces xenogeneic epitopes into the patient toward which deleterious immune responses are directed, decreasing the effectiveness of the scaffold. ECM scaffolds produced in vitro have potential to minimize the foreign body response, as ECM can be cultured using human cell lines and decellularized to produce an allogeneic scaffold with high biocompatibility. The primary challenge of producing ECM-based therapeutics in vitro is fabricating such material in a manner which approximates the composition and architecture of native matrix while maintaining high yield and ease-of-handling. In previous work, we have demonstrated that sacrificial open-cell foams can be used for the production of ECM scaffolds with properties approximating those of native tissues.1 Herein we demonstrate a novel approach for the production of continuous threads of extracellular matrix by statically culturing ECM-secreting fibroblasts in the lumina of mesoporous hollow fiber membranes (HFMs). This approach exploits the fact that mesoporous HFMs prevent cross-membrane transport of high molecular weight proteins produced by cells in their lumina, while allowing for diffusion of low molecular weight cell medium components. Please click Additional Files below to see the full abstract

Hypertensive Cardiotoxicity in Cancer Treatment-Systematic Analysis of Adjunct, Conventional Chemotherapy, and Novel Therapies-Epidemiology, Incidence, and Pathophysiology

Cardiotoxicity is the umbrella term for cardiovascular side effects of cancer therapies. The most widely recognized phenotype is left ventricular dysfunction, but cardiotoxicity can manifest as arrhythmogenic, vascular, myocarditic and hypertensive toxicities. Hypertension has long been regarded as one of the most prevalent and modifiable cardiovascular risk factors in the general population, but its relevance during the cancer treatment journey may be underestimated. Hypertensive cardiotoxicity occurs de novo in a substantial proportion of treated cancer patients. The pathology is incompletely characterized—natriuresis and renin angiotensin system interactions play a role particularly in conventional treatments, but in novel therapies endothelial dysfunction and the interaction between the cancer and cardiac kinome are implicated. There exists a treatment paradox in that a significant hypertensive response not only mandates anti-hypertensive treatment, but in fact, in certain cancer treatment scenarios, hypertension is a predictor of cancer treatment efficacy and response. In this comprehensive review of over 80,000 patients, we explored the epidemiology, incidence, and mechanistic pathophysiology of hypertensive cardiotoxicity in adjunct, conventional chemotherapy, and novel cancer treatments. Conventional chemotherapy, adjunct treatments, and novel targeted therapies collectively caused new onset hypertension in 33–68% of treated patients. The incidence of hypertensive cardiotoxicity across twenty common novel therapies for any grade hypertension ranged from 4% (imatinib) to 68% (lenvatinib), and high grade 3 or 4 hypertension in <1% (imatinib) to 42% (lenvatinib). The weighted average effect was all-grade hypertension in 24% and grade 3 or 4 hypertension in 8%

The Hurst Exponent of Fermi GRBs

Using a wavelet decomposition technique, we have extracted the Hurst exponent for a sample of 46 long and 22 short Gamma-ray bursts (GRBs) detected by the Gamma-ray Burst Monitor (GBM) aboard the Fermi satellite. This exponent is a scaling parameter that provides a measure of long-range behavior in a time series. The mean Hurst exponent for the short GRBs is significantly smaller than that for the long GRBs. The separation may serve as an unbiased criterion for distinguishing short and long GRBs.Comment: Accepted for publication in Monthly Notices of the Royal Astronomical Societ