No description available.

To determine the effects of spaceflight on the mucin layer of uterine tubes, female mice were subjected to simulated microgravity and/or low dose rate radiation (LDR). Astronaut age-appropriate (6 months old), female C57BL/6 mice were exposed to anti-orthostatic tail suspension (AOS) for up 21 days to model the unloading, fluid shift, and physiological stress aspects of the microgravity component. Subsets of mice were also exposed to whole-body, gamma-irradiation (0.04Gy at 0.01cGy/h) using 57Co plates to simulate the LDR radiation component. Mice were then euthanized at 1, 4 or 9 months after the 21 day simulation. Tissues were harvested and quantitatively analyzed for mucin production by measuring the mucin layer thickness of the isthmus, ampulla, and infundibulum regions of the uterine tubes. Analyses conducted indicate that there were no significant reductions in the isthmus and ampulla sections across all treatment groups at the 1, 4, and 9 month time samples. The infundibulum section showed significant reductions at 4 and 9 months post treatment, but there was not a significant change in thickness at 1 month post treatment. These data indicate that both simulated microgravity and radiation exposure cause a thinning of the mucin layer in the infundibulum region of the uterine tube, but do not cause significant morphological changes in the isthmus and ampulla sections of the tube.

While many studies have shown harmful effects of space flight on many tissues and systems of the human body, few studies have been done on the effects of space flight on the reproductive system. While the microgravity conditions of space flight are common knowledge, there is another component of space flight, that being higher than ambient (on Earth) levels of radiation. The purpose of this study was to examine the effects of simulated space flight on follicular development in the ovaries of mice, and to determine which component of spaceflight, i.e. microgravity, radiation, or a combination of the two, might be responsible for any changes in this follicular development. To simulate the environment of space, mice were exposed to higher levels of radiation by the use of cobalt plates and to simulated microgravity using a technique known as hind limb unloading. Four groups of mice-were used in this study; a control or untreated group, a group exposed to higher levels of radiation, a group exposed to simulated microgravity, and a group treated in both high radiation and simulated microgravity. The mice were further subdivided within these groups based on the amount of time they were kept alive after treatment/exposure (one, four, and nine months). The ovarian tissues were then analyzed to see the effects of these simulated conditions on the development of follicles. In all three treatment groups, development of follicles was restricted compared to the control group. Follicles from the various treatment groups appeared to be in the early stages of their development. It should be noted that these are preliminary results as the study is still in progress. One of the overarching questions that has been put forth by NASA over the last few decades is, can an organism, in this case a mammalian organism, complete an entire life cycle in space? This study may help to answer some of that question. If any of the components of space flight proves to be harmful to the female reproductive tissues human colonization of space would be problematic. If the damage incurred during space flight is irreversible, colonization of other worlds would also be problematic.

Numerous studies have indicated that the microgravity environment of space has harmful effects on several tissues throughout the body. Although this phenomenon is well documented, research in this area is still in its relative infancy. This study investigates the effects of space flight on mucin production of the uterine tubes of mice. This study examined the epithelium of the uterine tubes from female mice that were flown on the space shuttle Endeavour for 13 days in August, 2007 and their concomitant controls. The tissue was qualitatively analyzed for the type of mucin produced, i.e.; acidic, neutral, acidic/neutral mixture. Further, the tissue was quantitatively analyzed for the amounts of mucins produced by measuring the thickness of the mucin layer for each region of the uterine tube: isthmus, ampulla, and infundibulum. One way ANOVA tests were used to compare mucin thickness between all three sets of animals. Results indicate similar but not identical results between the three regions of the uterine tube. The Baseline tissue had the thickest mucin layer regardless of treatment group. In the ampulla the mucin layer was the thinnest in the Flight tissue, followed by the Ground Control, with the Baseline being the thickest. Analysis of the mucin layer of the infundibulum of the three treatment groups indicated no difference in its thickness between the three regions of the uterine tube. These results indicate a trend toward thinning of the mucin layer of the uterine tube in space flight, but also indicate an influence by the housing environment.

Numerous studies have indicated that the microgravity environment of space has harmful effects on several tissues throughout the body. Although this phenomenon is well documented, research in this area is still in its relative infancy. This study investigates the effects of space flight on mucin production of the uterine tubes of mice. This study examined the epithelium of the uterine tubes from female mice that were flown on the space shuttle Endeavour for 13 days in August, 2007 and their concomitant controls. The tissue was qualitatively analyzed for the type of mucin produced, i.e.; acidic, neutral, acidic/neutral mixture. Further, the tissue was quantitatively analyzed for the amounts of mucins produced by measuring the thickness of the mucin layer for each region of the uterine tube: isthmus, ampulla, and infundibulum. One way ANOVA tests were used to compare mucin thickness between all three sets of animals. Results indicate similar but not identical results between the three regions of the uterine tube. The Baseline tissue had the thickest mucin layer regardless of treatment group. In the ampulla the mucin layer was the thinnest in the Flight tissue, followed by the Ground Control, with the Baseline being the thickest. Analysis of the mucin layer of the infundibulum of the three treatment groups indicated no difference in its thickness between the three regions of the uterine tube. These results indicate a trend toward thinning of the mucin layer of the uterine tube in space flight, but also indicate an influence by the housing environment.

Space flight has been shown to have many adverse effects on various systems throughout the body. Because the opportunity to place research animals on board a Space Shuttle or the International Space Station is infrequent, various techniques have been designed to simulate the effects of microgravity in Earth based laboratories. A commonly used technique is known as antiorthostatic suspension, also often referred to as hind limb suspension. In this technique the hind portion of the animal is raised so that its hind limbs are non-weight bearing. This places the animal in roughly a 30° head down tilt position. This results in cephalic fluid shifts similar to those seen in actual space flight. This technique has also been shown to mimic other physiological parameters that are affected during space flight. This study examined testicular tissue from rats subjected to a 7 day antiorthostatic suspension. This tissue was acquired through a tissue sharing program and some of the experimental animals were injected with Interleukin 1 receptor antagonist (IL-1ra) which was hoped to ameliorate some of the effects of antiorthostatic suspension. The injection of IL-1ra was not expected to have any effect on testicular tissue, however this tissue was included in the morphological and statistical analysis to conduct a more complete study. All tissues were embedded in paraffin, sectioned, and stained using standard H&E staining. The tissue was then qualitatively ranked according to the "health" of the seminiferous tubules. Our findings indicate that 7 days of antiorthostatic suspension had adverse effects on the tissue that comprises the walls of the seminiferous tubules. It has long been known that antiorthostatic suspension has deleterious effects on testicular tissue, however this research indicates that these effects occur much faster than indicated by previous researchers. This is a significant finding because it indicates that meaningful earth based studies in this area can be carried out in a shorter time span. This could result in more studies per year as well as saving money by avoiding longer than necessary animal suspensions. This is especially important as we enter an era when, without Space Shuttle, flight opportunities will become scarce. These antiorthostatic suspension studies indicate that space flight, even short duration spaceflight, may have harmful effects on the seminiferous tubules and blood-testis barrier of astronauts.

No description available.

One of the main questions put forth by NASA and the European Space Agency (ESA) is whether or not an organism, especially mankind, can complete an entire life cycle in space. With this in mind, it is essential to study the effect of spaceflight on reproductive tissues. Using simulated microgravity techniques and whole-body radiation we sought to determine if females subjected to a simulated spaceflight environment have increased incidences of uterine cancer. Uterine tissue from mice subjected to simulated spaceflight was analyzed using immunohistochemical staining and western blot analysis. Two pathways commonly activated in cancer were investigated. Additionally, the uterine tissue was evaluated for gross morphological changes using standard histological staining. The findings of this study indicate that none of the treatment parameters used to simulate the spaceflight environment were found to induce uterine cancer.

<p>The aim of the project is to collect empirical data on contact line motion in vibrating tanks under zero-gravity (zero-g) conditions. This study is particularly focused on the behavior of current green propellants, which have a high contact angle compared to traditional stores like water. As a result, the non-linear contact line and angle is expected to have a significant impact on zero-g behavior. The thesis focuses on the dynamic experiment of developing an experimental payload designed to fly on Blue Origin\textquotesingle s New Shepherd suborbital flight. The data collected from this experiment will provide a benchmark case for developers of zero-g fluid dynamics simulations to compare or improve their simulation results. The results will also be useful for testing non-linear hysteresis contact line simulations.</p> <p><br></p> <p>The design of the experiment mainly focuses on conducting oscillatory motion in zero gravity to observe the contact line at varying speeds. Two different liquids are intended to be tested on the same payload. The liquid is to be filled so that the free surface has a height of 1 inch, and the vibration amplitude is to be 0.1 inches. The liquid chosen closely simulates the current green propellants under development or other poorly-wetting liquids. The purpose of each of the components used in the experiment is justified with respect to the given flight design constraints, along with how the constraints impacted the experiment. The experiment is designed to sustain the forces in case of hard landing during the flight and autonomous control of motion. The experiment is staged to be ready for flight on the New Shepherd, and any future works are mentioned. </p> <p><br></p> <p>To meet these constraints, the experimental payload is designed with a variety of components, each chosen for its ability to perform under the given conditions. The payload includes a custom-built system, which generates the oscillatory motion necessary to observe the contact line behavior. The system is designed to be compact and lightweight, yet robust enough to withstand the forces of launch and landing. In addition, the payload includes a custom-built tank designed to hold the liquids being tested. The study of contact line motion in vibrating tanks under zero-g conditions is important in understanding the behavior of liquids in space. This study will provide crucial data that will help in the development of more accurate fluid dynamic simulations for future space missions.</p>

Bone is a metabolically active tissue that is continuously remodeled throughout life. Osteocytes, the most abundant cells in bone, regulate bone homeostasis in response to hormonal and mechanical cues. Parathyroid hormone (PTH), a calciotropic hormone secreted from the parathyroid glands, has been widely used in the clinic to treat age-related osteoporosis. PTH acts on cells of the osteoblast lineage, including osteocytes, by signaling via the PTH receptor (PPR) to promote bone formation. However, the role of PPR signaling in osteocytes during aging has not been investigated. The hypothesis of this study is that PPR signaling in osteocytes plays a key role in maintaining skeletal health in aging mice. To address this hypothesis, mice in which the PPR was ablated in mature osteoblasts/osteocytes (Dmp1-Cre+;PPRfl/fl or Dmp1-PPRKO) were used to study their skeletal phenotype at 4 and 13 months of age. Compared to control littermates (Dmp1-Cre–;PPRfl/fl), Dmp1-PPRKO animals displayed age-dependent osteopenia due to reduced osteoblast activity and increased osteoclast numbers and activity. These changes were associated with a significant decrease in osteoprogenitors and an increase in marrow adiposity. At the molecular level, the absence of PPR signaling in mature osteoblasts/osteocytes was accompanied by a marked increase in serum sclerostin, RANKL-expressing marrow adipocytes, and early onset of oxidative stress in osteocytes. In vitro studies demonstrated that PTH protected osteocytes from oxidative stress-induced cell death by suppressing the intracellular accumulation of reactive oxygen species. Mechanical forces are also important regulators of bone mass and quality. For instance, immobilization and reduced mechanical loading, such as prolonged bed rest or long-duration spaceflight, lead to bone loss or osteopenia due to reduced bone formation and increased bone resorption. Osteocytes are known to sense and transduce mechanical forces applied to the skeleton into biochemical signals. However, the exact molecular mechanism remains unclear. To unravel the mechanism by which osteocytes sense and respond to mechanical unloading, an osteocytic cell line, Ocy454, was exposed to microgravity (µG) conditions for 2, 4, or 6 days onboard the SpaceX Dragon-6 and the International Space Station. Global transcriptomic analysis demonstrated that µG leads to downregulation of key osteocytic marker genes compared to ground controls (1G), suggesting the impaired differentiation of osteocytes. Importantly, glycolysis was the most activated signaling pathway in osteocytes subjected to µG compared to 1G. Gene comparison analysis further identified a set of mechano-sensitive genes that are consistently regulated in multiple types of cells exposed to µG, suggesting a common, yet to be fully elucidated, genome-wide response to µG. In summary, these studies demonstrated that osteocytes are highly regulated by PTH and mechanical forces. We found that PPR signaling in osteocytes is important for protecting the skeleton from age-induced osteopenia by promoting osteoblast’s bone-forming activity and mitigating osteoclast’s bone resorption. We also demonstrated that PTH protects osteocytes from oxidative stress. Finally, we showed that osteocytes respond to µG with an increase in glucose metabolism and oxygen consumption.