The Blood-Oocyte Barrier: Morphological Evidence Implicating The Zona Pellucida

A developing oocyte is capable of synthesizing non-self proteins recognized as foreign by the maternal immune system. Since the oocyte may be perceived as foreign it must be protected from interaction with the immune system in order for it to mature to the point of ovulation. Oocytes that begin development but do not mature to the point of ovulation become atretic and are destroyed and phagocytized by the maternal system. This study proposes that the zona pellucida of the ovarian follicle is the barrier between the immune system and the oocyte. The suggestion is made that the oocyte may play a role in blocking the immune system during its maturation, and follicles in which the oocyte is incapable of providing for its own protection become atretic. Indirect immunolabelling techniques employing both peroxidase and fluorochrome-conjugated antibodies were used to assess the presence of immunoglobulin G, female protein, and albumin in the ovary of the golden hamster Mesocricetus auratus. This experimental technique indicates that immunoglobulin G, female protein, and albumin are found localized in the zona pellucida and liquor folliculi of ovarian follicles. Intravenous injection of fluorescein-conjugated hamster immunoglobulin G demonstrates the ability of the zona pellucida to limit access of serum immunoglobulin G to the oocyte. The labelled immunoglobulin G circulates rapidly through the animal and does not appear to be impeded in its access to the follicle. It accumulates rapidly in the liquor folliculi and zona pellucida yet never appears within the perivitelline space. The results of this study suggest that the zona pellucida is responsible for separating the developing oocyte from the maternal immune system, thus forming a blood-oocyte barrier to immunoglobulins. Further speculation is made that the oocyte plays a role in its own protection by production of factors capable of blocking complement fixation. If incapable of providing for its own protection, the oocyte is acted upon by the maternal immune system. The zona pellucida and liquor folliculi aid the immune system by providing an area for local storage of proteins necessary to accomplish complement fixation and subsequent follicular atresia

The Effects of a High Caloric Diet and CTRP3 Over-expression on the Myometrium of the Mouse Uterus

One of the major healthcare issues found almost worldwide, especially in the United States, is the obesity epidemic. Obesity is known to have deleterious effects on many body/organ systems. C1q TNF-related protein-3 (CTRP3) is effective at preventing high-fat diet-induced fatty liver. With these two factors taken into consideration, this study explores the possible effects of a high caloric diet on the muscle wall of the uterus, i.e., the myometrium, and how over-expression of CTRP3 may modify those effects. We hypothesize that consumption of excessive amounts of fat and sugar will have detrimental effects on the dual layers of the mouse myometrium. For this study, 17 mice were divided into 4 treatment groups: wild type/low fat diet, wild type/high fat diet, CTRP3-overexpressing/low fat diet, and CTRP3-overexpressing/high fat diet. The mice were placed on their respective diets at 7 weeks of age with a feeding duration of 12 weeks. At the conclusion of the feeding protocol, the female reproductive tissues were harvested and fixed in 4% paraformaldehyde and subsequently paraffin embedded. The uterine horns of each mouse were painstakingly paraffin embedded in a vertical position so that cross sections of the uterus could be obtained and measured. These 4µ sections were stained using standard H&E staining techniques and visualized under light microscopy. A randomization grid was utilized to determine measurement locations on the tissue. For each animal, 15 measurements were made of the outer longitudinal layer of the uterine horn, as well as 15 measurements of the inner circular layer, and 15 measurements of the thickness of the two layers combined. Two-way ANOVA was used to determine if any changes seen were statistically significant. At the time of the writing of this abstract, no appreciable differences have been found between the treatment groups, although there will be more data and final statistics completed before the presentation of our findings

Using a disciplinary discourse lens to explore how representations afford meaning making in a typical wave physics course

We carried out a case study in a wave physics course at a Swedish university in order to investigate the relations between the representations used in the lessons and the experience of meaning making in interview–discussions. The grounding of these interview–discussions also included obtaining a rich description of the lesson environment in terms of the communicative approaches used and the students’ preferences for modes of representations that best enable meaning making. The background for this grounding was the first two lessons of a 5-week course on wave physics (70 students). The data collection for both the grounding and the principal research questions consisted of video recordings from the first two lessons: a student questionnaire of student preferences for representations (given before and after the course) and video-recorded interview–discussions with students (seven pairs and one on their own). The results characterize the use of communicative approaches, what modes of representation were used in the lectures, and the trend in what representations students’ preferred for meaning making, all in order to illustrate how students engage with these representations with respect to their experienced meaning making. Interesting aspects that emerged from the study are discussed in terms of how representations do not, in themselves, necessarily enable a range of meaning making; that meaning making from representations is critically related to how the representations get situated in the learning environment; and how constellations of modes of disciplinary discourse may be necessary but not always sufficient. Finally, pedagogical comments and further research possibilities are presented.Web of Scienc

Invading and expanding : range dynamics and ecological consequences of the Greater White-Toothed Shrew (Crocidura russula) invasion in Ireland

Establishing how invasive species impact upon pre-existing species is a fundamental question in ecology and conservation biology. The greater white-toothed shrew (Crocidura russula) is an invasive species in Ireland that was first recorded in 2007 and which, according to initial data, may be limiting the abundance/distribution of the pygmy shrew (Sorex minutus), previously Ireland’s only shrew species. Because of these concerns, we undertook an intensive live-trapping survey (and used other data from live-trapping, sightings and bird of prey pellets/nest inspections collected between 2006 and 2013) to model the distribution and expansion of C. russula in Ireland and its impacts on Ireland’s small mammal community. The main distribution range of C. russula was found to be approximately 7,600 km2 in 2013, with established outlier populations suggesting that the species is dispersing with human assistance within the island. The species is expanding rapidly for a small mammal, with a radial expansion rate of 5.5 km/yr overall (2008–2013), and independent estimates from live-trapping in 2012–2013 showing rates of 2.4–14.1 km/yr, 0.5–7.1 km/yr and 0–5.6 km/yr depending on the landscape features present. S. minutus is negatively associated with C. russula. S. minutus is completely absent at sites where C. russula is established and is only present at sites at the edge of and beyond the invasion range of C. russula. The speed of this invasion and the homogenous nature of the Irish landscape may mean that S. minutus has not had sufficient time to adapt to the sudden appearance of C. russula. This may mean the continued decline/disappearance of S. minutus as C. russula spreads throughout the island

The Effects of Simulated Microgravity on the Seminiferous Tubules of Rats

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

The Effects of a High Fat/High Sugar Diet on the Myometrium

This study comprises the ramifications of a diet high in fat and sugar contents that manifest in the uterus. What a clinical setting deems excessive is unfortunately a societal norm in terms of diet. For this reason, it is of a critical nature to investigate the consequences of diets high in sugar and fat contents for the sake of women’s health. Our hypothesis is that consumption of excessive amounts of fat and sugar will have detrimental effects on the muscle layers of the uterus, the myometrium. Since much of the research concerning uterine tissue behavior involves aspects such as pregnancy and fertility assays, this study does not include such facets. The uterine horns of nine high sugar/high fat diet fed mice were collected and transversely sectioned in order to measure the thickness of each uterine layer. At the time of this submission measurements were still being taken and statistical analyses has not yet been completed

The Effects of Simulated Space Flight on Ovarian Tissue

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

Effects of Spaceflight on the Muscular Layers of Mouse Uterine Tissue

As NASA and other space programs around the world prepare to send astronauts into space for longer missions, it is becoming imperative to understand the biological effects of spaceflight on the human body. In order to better understand how the long-term spaceflight environment affects humans biologically, researchers often utilize other model organisms, like mice, whose biological systems are comparable to human body systems. Our study was performed to determine if spaceflight had any effect on the thickness of the muscular layers of the uterine tissue of female mice. In other words, how does the thickness of the muscular layers in the uterus of spaceflight mice compare to that of control mice that were not subjected to spaceflight. For this study mice were divided into 4 groups (flight animals, baseline animals, vivarium controls, and ground controls) and the flight mice subjected to 37 days of spaceflight. Upon tissue retrieval and histological preparation, five random measurements of the outer longitudinal muscular layer and five random measurements from the inner circular muscular layer of each tissue sample were made. The average thickness for each layer was then calculated and statistical analysis used to determine differences between the four groups of mice. At the time of this presentation final measurements and statistics had not been completed

The Effect of the Space Flight Environment on Mucin Production in the Mouse Uterine Tube

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

Does Transgenic Overexpression of Ctrp3 Alter Kidney Morphology?

C1q TNF-related protein-3 (CTRP3) is effective at preventing high-fat diet-induced fatty liver; Recent studies have shown that overexpression of C1q TNF-related protein-3 (CTRP3) in mice fed a high alcohol diet can protect the animal from developing fatty liver disease, and therefore may be a possible treatment for alcoholic fatty liver disease (ALD). However, the possible effects of overexpression of CTRP3 on other tissue has not been widely investigated. If overexpression of CTRP3 proves to be harmful to other tissues, its use as a treatment for ALD would come into question. This study utilized kidney tissue from mice that were fed a high fat diet for 13-14 weeks. The feeding started when the mice were 7 weeks old and continued for 9 weeks. The mice were divided into 4 categories: wild-type/low fat diet, wild-type/high fat diet, transgenic/low fat diet, and transgenic/high fat diet. The kidneys were harvested and fixed in 4% paraformaldehyde and subsequently paraffin embedded. Sections were cut at 4µ and stained using three different staining techniques: standard H&E, Periodic Acid Schiff (PAS), and Masson’s Trichrome Staining. These three methods were utilized to better visualize possible effects on the tissue, i.e. changes in connective tissue deposition or basement membrane thicknesses, etc. Light microscopic examination of the tissues to date has revealed abnormalities in some of the kidney tubules in the transgenic high fat diet group. These same abnormalities have not been observed in the other treatment groups. This study is still in its early stages and much more in-depth investigation is needed to determine which of the tubules of the nephron are affected, and what this effect is. If this study confirms that overexpression of CTRP3 coupled with a high fat diet is harmful to kidney tissues, the use of CTRP3 in the treatment of ALD would require careful monitoring of the patient’s diet