The Effect of Spaceflight on Bone Cell Cultures

Understanding the response of bone to mechanical loading (unloading) is extremely important in defining the means of adaptation of the body to a variety of environmental conditions such as during heightened physical activity or in extended explorations of space or the sea floor. The mechanisms of the adaptive response of bone are not well defined, but undoubtedly they involve changes occurring at the cellular level of bone structure. This proposal has intended to examine the hypothesis that the loading (unloading) response of bone is mediated by specific cells through modifications of their activity cytoskeletal elements, and/or elaboration of their extracellular matrices. For this purpose, this laboratory has utilized the results of a number of previous studies defining molecular biological, biochemical, morphological, and ultrastructural events of the reproducible mineralization of a primary bone cell (osteoblast) culture system under normal loading (1G gravity level). These data and the culture system then were examined following the use of the cultures in two NASA shuttle flights, STS-59 and STS-63. The cells collected from each of the flights were compared to respective synchronous ground (1G) control cells examined as the flight samples were simultaneously analyzed and to other control cells maintained at 1G until the time of shuttle launch, at which point they were terminated and studied (defined as basal cells). Each of the cell cultures was assayed in terms of metabolic markers- gene expression; synthesis and secretion of collagen and non-collagenous proteins, including certain cytoskeletal components; assembly of collagen into macrostructural arrays- formation of mineral; and interaction of collagen and mineral crystals during calcification of the cultures. The work has utilized a combination of biochemical techniques (radiolabeling, electrophoresis, fluorography, Western and Northern Blotting, and light microscopic immunofluorescence) and structural methods (conventional and high voltage electron microscopy, inununocytochemistry, stereomicroscopy, and 3D image reconstruction). The studies have provided new knowledge of aspects of bone cell development and structural regulation, extracellular matrix assembly, and mineralization during spaceflight and under normal gravity. The information has contributed to insights into the means in general by which cells respond and adapt to different conditions of gravity (loading). The data may as well have suggested an underlying basis for the observed loss of bone by vertebrates, including man, in microgravity; and these scientific results may have implications for understanding bone loss following fracture healing and extended periods of inactivity such as during long-term bedrest

Gene Expression of Tissue-Engineered Distal Phalanx Models Utilizing Polymer Scaffolds with Hydroxyapatite and Beta-Tricalcium Phosphate

Tissue engineering is a scientific methodology that provides the means for fabrication of vital tissues in a laboratory with the ultimate goal of translating the tissue to a patient in a clinic. It is a desirable technique in clinical medicine because it eliminates the need for patient tissue grafts and transplants, which have the potential for donor site morbidity and rejection. In tissue engineering, the scaffolding material, typically a polymer upon which tissue is grown, is important. The goal of this research is to investigate optimization of tissue-engineered polymer scaffold constructs for cell proliferation and gene expression. This work includes an analysis of scaffold type to determine the appropriate engineered materials for growing human periosteum. Many scaffolding materials have been investigated for tissue-engineering purposes; however, the present study will be examining novel scaffolds for growing periosteum, those scaffolds being composed of hydroxyapatite (HA) or beta-tricalcium phosphate (β-TCP) with polylactic acid/polycaprolinic acid [P(LA/CL)]. To conduct this analysis, histology of tissue-engineered constructs will be utilized to determine cell proliferation, and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) will be applied to determine gene expression of construct cells. Results will be compared to determine differences in fold-change expression levels of several genes of interest that may be affected by the two different scaffolds. The initial findings of the study showed that there were few significant differences in gene expression between the scaffolds composed of HA or β-TCP

Life Cycle Assessment of Bioplastics and Food Waste Disposal Methods

The environmental impacts of five waste management scenarios for polylactic acid (PLA)-based bioplastics and food waste were quantified using life cycle assessment. Laboratory experiments have demonstrated the potential for a pretreatment process to accelerate the degradation of bioplastics and were modeled in two of the five scenarios assessed. The five scenarios analyzed in this study were: (1a) Anaerobic digestion (1b) Anaerobic digestion with pretreatment; (2a) Compost; (2a) Compost with pretreatment; (3) Landfill. Results suggested that food waste and pretreated bioplastics disposed of with an anaerobic digester offers life cycle and environmental net total benefits (environmental advantages/offsets) in several areas: ecotoxicity (−81.38 CTUe), eutrophication (0 kg N eq), cumulative energy demand (−1.79 MJ), global warming potential (0.19 kg CO2), and human health non-carcinogenic (−2.52 CTuh). Normalized results across all impact categories show that anaerobically digesting food waste and bioplastics offer the most offsets for ecotoxicity, eutrophication, cumulative energy demand and non-carcinogenic. Implications from this study can lead to nutrient and energy recovery from an anaerobic digester that can diversify the types of fertilizers and decrease landfill waste while decreasing dependency on non-renewable technologies. Thus, using anaerobic digestion to manage bioplastics and food waste should be further explored as a viable and sustainable solution for waste management

Guidance and Navigation for Rendezvous and Proximity Operations with a Non-Cooperative Spacecraft at Geosynchronous Orbit

The feasibility and benefits of various spacecraft servicing concepts are currently being assessed, and all require that the servicer spacecraft perform rendezvous, proximity, and capture operations with the target spacecraft to be serviced. Many high-value spacecraft, which would be logical targets for servicing from an economic point of view, are located in geosynchronous orbit, a regime in which autonomous rendezvous and capture operations are not commonplace. Furthermore, existing GEO spacecraft were not designed to be serviced. Most do not have cooperative relative navigation sensors or docking features, and some servicing applications, such as de-orbiting of a non-functional spacecraft, entail rendezvous and capture with a spacecraft that may be non-functional or un-controlled. Several of these challenges have been explored via the design of a notional mission in which a nonfunctional satellite in geosynchronous orbit is captured by a servicer spacecraft and boosted into super-synchronous orbit for safe disposal. A strategy for autonomous rendezvous, proximity operations, and capture is developed, and the Orbit Determination Toolbox (ODTBX) is used to perform a relative navigation simulation to assess the feasibility of performing the rendezvous using a combination of angles-only and range measurements. Additionally, a method for designing efficient orbital rendezvous sequences for multiple target spacecraft is utilized to examine the capabilities of a servicer spacecraft to service multiple targets during the course of a single mission

A computer program for the generalized chi-square analysis of categorical data using weighted least squares (GENCAT)

GENCAT is a computer program which implements an extremely general methodology for the analysis of multivariate categorical data. This approach essentially involves the construction of test statistics for hypotheses involving functions of the observed proportions which are directed at the relationships under investigation and the estimation of corresponding model parameters via weighted least squares computations. Any compounded function of the observed proportions which can be formulated as a sequence of the following transformations of the data vector -- linear, logarithmic, exponential, or the addition of a vector of constants -- can be analyzed within this general framework. This algorithm produces minimum modified chi-square statistics which are obtained by partitioning the sums of squares as in ANOVA. The input data can be either: (a) frequencies from a multidimensional contingency table; (b) a vector of functions with its estimated covariance matrix; and (c) raw data in the form of integer-valued variables associated with each subject. The input format is completely flexible for the data as well as for the matrices.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/21627/1/0000006.pd

Evaluation of Tissue-engineered Tendon Enthesis Polymer Constructs

Both scientists and clinicians have proposed tissue engineering as the future of medicine. The possibilities for tissue engineering, that is, fabrication of tissues and organs in the laboratory and their translation to patients, appear to be endless, and many believe that this new approach in medicine will result in abolishing many common ailments, injuries, and congenital defects. Injuries to a tendon enthesis, the normal tissue connection between tendon and bone, are of particular concern to clinicians because of their frequency and failure to repair as a result of surgery. While these injuries may not be life threatening, they can certainly limit mobility and reduce the quality of life in those affected individuals. Fabrication of a tendon enthesis by tissue engineering would offer an alternative to the routine of surgery now performed and present potential for treatment and healing of the tissue now unavailable. In the current prospective study, polymer scaffolds created using polycaprolactone (PCL), poly-L lactide (PLLA), or nano-polyglycolic acid (nPGA) were seeded with chondrocytes, tenocytes, and periosteum for the development of cartilage, tendon and bone, respectively, and then implanted into six athymic nude mice for a period of 10 weeks. One group of constructs (scaffolds and cells or tissue together) was tethered to the mice 2 in order to determine if mechanical forces improved or were required for tendon enthesis formation compared to a group of identical implanted constructs that were not tethered. Analysis by histology illustrated a noticeable increase in tissue formation around the area of anticipated enthesis in tethered constructs when compared to constructs that were not tethered. Based on these data, it is believed that mechanical tension (tethering) is required for the formation of a tendon enthesi

Parent and child agreement for acute stress disorder, post-traumatic stress disorder and other psychopathology in a prospective study of children and adolescents exposed to single-event trauma

Examining parent-child agreement for Acute Stress Disorder (ASD) and Post-Traumatic Stress Disorder (PTSD) in children and adolescents is essential for informing the assessment of trauma-exposed children, yet no studies have examined this relationship using appropriate statistical techniques. Parent-child agreement for these disorders was examined by structured interview in a prospective study of assault and motor vehicle accident (MVA) child survivors, assessed at 2-4 weeks and 6 months post-trauma. Children were significantly more likely to meet criteria for ASD, as well as other ASD and PTSD symptom clusters, based on their own report than on their parent's report. Parent-child agreement for ASD was poor (Cohen's κ = -.04), but fair for PTSD (Cohen's κ = .21). Agreement ranged widely for other emotional disorders (Cohen's κ = -.07-.64), with generalised anxiety disorder found to have superior parent-child agreement (when assessed by phi coefficients) relative to ASD and PTSD. The findings support the need to directly interview children and adolescents, particularly for the early screening of posttraumatic stress, and suggest that other anxiety disorders may have a clearer presentation post-trauma

Stroke Ready: a multi-level program that combines implementation science and community-based participatory research approaches to increase acute stroke treatment: protocol for a stepped wedge trial

Abstract Background Post-stroke disability is common, costly, and projected to increase. Acute stroke treatments can substantially reduce post-stroke disability, but few patients take advantage of these cost-effective treatments. Practical, cost-efficient, and sustainable interventions to address underutilized acute stroke treatments are currently lacking. In this context, we present the Stroke Ready project, a stepped wedge design, multi-level intervention that combines implementation science and community-based participatory research approaches to increase acute stroke treatments in the predominately African American community of Flint, Michigan, USA. Methods Guided by the Tailored Implementation of Chronic Disease (TICD) framework, we begin with optimization of acute stroke care in emergency departments, with particular attention given to our safety-net hospital partners. Then, we move to a community-wide, multi-faceted, stroke preparedness intervention, with workshops led by peer educators, over 2 years. Measures of engagement of the safety-net hospital and the feasibility and sustainability of the implementation strategy as well as community intervention reach, dose delivered, and satisfaction will be collected. The primary outcome is acute stroke treatment rates, which includes both intravenous tissue plasminogen activator, and endovascular treatment. The co-secondary outcomes are intravenous tissue plasminogen activator treatment rates and the proportion of stroke patients who arrive by ambulance. Discussion If successful, Stroke Ready will increase acute stroke treatment rates through emergency department and community level interventions. The stepped wedge design and process evaluation will provide insight into how Stroke Ready works and where it might work best. By exploring the relative effectiveness of the emergency department optimization and the community intervention, we will inform hospitals and communities as they determine how best to use their resources to optimize acute stroke care. Trial registration ClinicalTrials.gov Trial Identifier NCT03645590 .https://deepblue.lib.umich.edu/bitstream/2027.42/148211/1/13012_2019_Article_869.pd