Matching Items (45)

137025-Thumbnail Image.png

7-deaza-dG Promotes the Faithful Transcription of 4 Nucleotide TNA Polymers

Description

DNA is a natural genetic polymer capable of storing and preserving genetic information in biological systems. Due to its natural information storage capacity, recent scientific progress demonstrates that DNA has

DNA is a natural genetic polymer capable of storing and preserving genetic information in biological systems. Due to its natural information storage capacity, recent scientific progress demonstrates that DNA has the potential to exceed standard information storage technologies. However, DNA is limited in its information storage capacities due to its susceptibility to degradation in the presence of naturally occurring nucleases. Threose nucleic acid (TNA), an unnatural genetic polymer with a 3'->2'phosphodiester-linked threose sugar backbone, has promising potential to overcome this limitation. TNA is not a substrate for natural nucleases and thus shows a dramatic increase in stability compared to DNA. However, TNA transcription has a tendency to generate G:G mispairs and lead to a gradual loss of information within the template. It was hypothesized that the mutation occurs through a G:G Hoogsteen base pair that forms preferentially over the canonical G:C Watson-Crick base pair. Incorporation of 7-deaza-dG into a four letter template effectively eliminated G:G mispairings and improved the replication fidelity from 60% to 99.6% with only four errors in a thousand. These results have laid the groundwork for further research to increase the length of the TNA product synthesized and to test TNA's ability to store genetic information.

Contributors

Agent

Created

Date Created
  • 2014-05

Elucidating the Role of PDK1 During Mitotic Cellular Division

Description

Phosphoinositol-Dependent Kinase 1 (PDK1) acts in conjunction with phosphorylated lipids such as Phosphoinositol-3,4,5-triphosphate (PIP3) to activate a variety of proteins that regulate mechanisms ranging from cell growth and survival to

Phosphoinositol-Dependent Kinase 1 (PDK1) acts in conjunction with phosphorylated lipids such as Phosphoinositol-3,4,5-triphosphate (PIP3) to activate a variety of proteins that regulate mechanisms ranging from cell growth and survival to cytoskeletal rearrangement. In this investigation PDK1 was examined in the context of cellular division. The techniques of immunocytochemistry and live cell imaging were used to visualize the effects of the inhibition of PDK1 on division in HeLa cells. Division was impaired at metaphase of mitosis. The inhibited cells were unable to initiate anaphase cell-elongation ultimately leading to the flattening of spherical, metaphase cells. Preliminary studies with imunocytochemistry and live cell imaging suggested that insulin treatment reversed PDK1 inhibition, but the results were not statistically significant. Therefore, the recovery of PDK1 inhibition by insulin treatment could not be confirmed. Based on these observations a possible reason for the inability of the treated cells to complete cytokinesis could be the role of PDK1 in the Rho-kinase pathway that is required for the processes cell-elongation necessary for anaphase of mitosis.

Contributors

Agent

Created

Date Created
  • 2014-05

137057-Thumbnail Image.png

Differential Activation of Unfolded Protein Response in Two Osteosarcoma Cell Lines Following Hypoxic and Chemotherapeutic Stress

Description

Osteosarcoma (OS) is the most prevalent primary tumor of bone in the pediatric age group [1]. The long-term cancer free survival has improved in patients with localized cancer; however, less

Osteosarcoma (OS) is the most prevalent primary tumor of bone in the pediatric age group [1]. The long-term cancer free survival has improved in patients with localized cancer; however, less than 20% of patients diagnosed with metastatic disease survive without relapse [2]. While these findings emphasize the urgent need for new therapeutic agents, the lack of understanding of the factors and the tumor microenvironment that lead to therapy resistance in OS has significantly hampered progress towards improved prognosis. Recent clinical reports have shown a negative correlation between tumor hypoxia and overall survival in OS patients [4]. In addition to the up-regulation of hypoxia inducible factors (HIFs), it has been shown that hypoxia can trigger an adaptive response such as the unfolded protein response (UPR) that allows tumor cells to avoid therapy-induced death [3,4,7,10].
Using in vitro experimental models of both SAOS-2 (non-metastatic) and 143-b (metastatic) osteosarcoma cell lines and Western blot analysis, we have demonstrated that basal levels of molecular chaperone BiP (Binding immunoglobulin protein, or GRP-78) and peIF2α (phospho-eukaryotic initiation factor 2 alpha), both markers of the UPR, were higher in SAOS-2 than 143-b cells. We also show that both these markers were further up-regulated upon exposure to hypoxia, as evidenced by the increase in banding intensity in both SAOS-2 and 143-b cells. Furthermore, analysis of another UPR marker, ATF6 (activating transcription factor 6) showed that basal levels of active nuclear ATF6 were slightly higher in SAOS-2 cells than in 143-b cells. However, unlike the other UPR markers these levels were significantly reduced upon exposure to hypoxia (0.1% O2). In addition to hypoxia, treatment with Cisplatin also had similar effects on the expression of aforementioned UPR markers: BiP and peIF2α. We found that the 143-b OS cells were more sensitive to the Cisplatin treatment than the SAOS-2 OS cells, and thus more prone to cell-mediated death.
Our findings shed light on the unknown mechanisms underlying chemotherapeutic drug resistance in osteosarcoma patients. Our research may lead to novel therapies that seek out and destroy the chemoresistant OS cells within the hypoxia core of tumors, thereby preventing survival and metastasis, and ultimately improving the chances of survival amongst OS patients.

Contributors

Agent

Created

Date Created
  • 2014-05

136859-Thumbnail Image.png

Understanding the Impact of Phytoestrogens on Memory & the Cholinergic System

Description

Menopause is reproductive senescence characterized by a loss of ovarian estrogen and progesterone. Women can experience cognitive decline and other negative symptoms with the loss of ovarian hormones (Sherwin, 2006).

Menopause is reproductive senescence characterized by a loss of ovarian estrogen and progesterone. Women can experience cognitive decline and other negative symptoms with the loss of ovarian hormones (Sherwin, 2006). While hormone therapies (HT) can treat symptoms of menopause and may have neuroprotective properties, such as the potential to decrease the risk of Alzheimer's Disease (Behl & Manthey, 2000), there are many effects of current HTs that are not ideal. Indeed, optimizing conventional HTs has proven complex, indicating a need for alternative therapies. Phytoestrogens are estrogenic compounds found naturally in plants such as soybeans, that could provide new treatment options. Dietary phytoestrogens can benefit memory in the rodent model (Luine, 2006), although the mechanism underlying these effects is unclear. Basal forebrain cholinergic projections have been shown to mediate the cognitive benefits of estrogen (Gibbs, 2010); we hypothesize that phytoestrogens act similarly, via the cholinergic system, to impact memory. We administered varying doses of phytoestrogen-containing diets to ovariectomized female rats, and used the place recognition task to evaluate spatial memory. Brains were then analyzed for choline acetyltransferase (ChAT), the synthesizing enzyme for acetylcholine, in the vertical-diagonal bands (VDB) and the medial septum (MS) of the basal forebrain. Results showed that ChAT cell counts in the VDB were marginally higher with dietary phytoestrogen treatment. Further, VDB ChAT cell counts positively correlated with place recognition performance, indicating that animals with more VDB ChAT neurons exhibited better spatial memory performance. These results suggest that phytoestrogens might act similarly to natural, endogenously circulating estrogens, and identify phytoestrogens as a direction for investigation as a HT.

Contributors

Created

Date Created
  • 2014-05

Comparing Nutritional Physiology and Bioavailable Nutrients between Rural and Urban Populations of Callipepla gambelii

Description

This study is an exploration of the nutritional physiology of Gambel's quail, Callipepla gambelii, in terms of the comparison of rural and urban area populations of this gallinaceous species, and

This study is an exploration of the nutritional physiology of Gambel's quail, Callipepla gambelii, in terms of the comparison of rural and urban area populations of this gallinaceous species, and the employment of in situ study by design. The health of quail populations is of interest as a resource to recreational enthusiasts, hunters, stakeholders, as well as agencies charged with their management. Quail are the only resident small avian game species known to be native to the southwest that is depended upon by management agencies for recreational opportunities. The condition of the Gambel's quail populations determine regulatory actions with respect to recreational quailing opportunities and these quail represent a species which shows adjustment to human expansion. The combination of morphologic, physical, and plasma nutrient data gathered from samples during this study are hypothesized to show a difference between rural and urban populations of C. gambelii. The hypothesis is that urban quail will display morphological differences, and nutrient differences that are crucial to quail fitness, therefore, potential selective differences. Ground and ambient air temperatures are hypothesized to be higher in urban areas andthus these measurements were taken for site comparison. Plasma nutrient concentrations between rural and urban populations of adult male Gambel's quail were compared for potential existing variations in nutrition. The blood nutrient assays are expected to display increased plasma concentrations of constituents such as glucose, lipids, and proteins, which are known to be involved in growth, reproductive success, and general fitness in the urban quail populations. Morphological data was collected to examine the potential differences in the physical attributes of the sampled quail. A fitness advantage in male Gambel's quail living within urban areas is hypothesized to be associated with differences in plasma nutrients and morphology. The potentially differing plasma nutrients in samples of the C. gambelii in urban versus rural environments is believed to be affected by, and to indicate, differing nutrient availability. Body mass and length, chest circumference as well as skin temperatures were measured to assess potential differences in these outward physical attributes. The urban quail are hypothesized to have reproductive and/or natural selective advantages where their measured morphology may show physical size differences. Differences in the physical attributes of the male Gambel's quail that live in urban areas may be supported through measured morphologic attributes.

Contributors

Agent

Created

Date Created
  • 2015-12

135346-Thumbnail Image.png

Adult Cytogenesis and Reproductive Regulation in the American Bullfrog

Description

The purpose of the present study was to investigate seasonal changes in cell proliferation in the brains of adult American bullfrog. Our main question was whether there are seasonal differences

The purpose of the present study was to investigate seasonal changes in cell proliferation in the brains of adult American bullfrog. Our main question was whether there are seasonal differences in the proliferation and/or differentiation of newborn brain cells into arginine vasotocin- (AVT) or gonadotropin releasing hormone- (GnRH) producing neurons that might regulate bullfrog reproduction. . Bullfrogs in four distinct seasonal groups received injections of bromodeoxyuridine (BrdU), a thymidine analog that is taken up by dividing cells, and then euthanized six weeks later. Using doubleimmunofluorescence procedures to visualize BrdU and AVT or GnRH, we found no evidence for newborn AVT- or GnRH-ergic cells, but observed newborn cells in close proximity to AVT and GnRH cells. My project was a follow-up study to explore seasonal changes in adult cytogenesis related to AVT and GnRH terminal fields. GnRH fiber density fluctuated seasonally in the rostral pre-optic area (RPOA) and lateral septum (LS), and newborn cell numbers changed seasonally in the amygdala (AM) and RPOA. Seasonal differences in plasma testosterone concentrations were negatively related to GnRH fiber density in the LS. These results reinforce the seasonality of reproductive signaling and adult cytogenesis and support a role for seasonal steroid-peptide hormone interactions in modulating GnRH levels. Our results suggest a relationship between seasonal adult cytogenesis and reproduction, and set the stage for further research into the nature of this relationship.

Contributors

Agent

Created

Date Created
  • 2013-05

134961-Thumbnail Image.png

A comparative test of the links between sleep state, brain size, and incubation investment in birds

Description

There are two electrophysiological states of sleep in birds (rapid-eye-movement sleep [REM] and slow-wave sleep [SWS]), which have different functions and costs. REM improves memory consolidation, while SWS is neuro-restorative but

There are two electrophysiological states of sleep in birds (rapid-eye-movement sleep [REM] and slow-wave sleep [SWS]), which have different functions and costs. REM improves memory consolidation, while SWS is neuro-restorative but also exposes the animal to more risk during this deep-sleep phase. Birds who sleep in more exposed microsites are known to invest proportionally less in SWS (presumably to ensure proper vigilance), but otherwise little else is known about the ecological or behavioral predictors of how much time birds devote to REM v. SWS sleep. In this comparative analysis, we examine how proportional time spent in SWS v. REM is related to brain mass and duration of the incubation period in adults. Brain mass and incubation period were chosen as predictors of sleep state investment because brain mass is positively correlated with body size (and may show a relationship between physical development and sleep) and incubation period can be a link used to show similarities and differences between birds and mammals (using mammalian gestation period). We hypothesized that (1) species with larger brains (relative to body size and also while controlling for phylogeny) would have higher demands for information processing, and possibly proportionally outweigh neuro-repair, and thus devote more time to REM and that (2) species with longer incubation periods would have proportionally more REM due to the extended time required for overnight predator vigilance (and not falling into deep sleep) while on the nest. We found, using neurophysiological data from literature on 27 bird species, that adults from species with longer incubation periods spent proportionally more time in REM sleep, but that relative brain size was not significantly associated with relative time spent in REM or SWS. We therefore provide evidence that mammalian and avian REM in response to incubation/gestation period have convergently evolved. Our results suggest that overnight environmental conditions (e.g. sleep site exposure) might have a greater effect on sleep parameters than gross morphological attributes.

Contributors

Agent

Created

Date Created
  • 2017-05

136349-Thumbnail Image.png

Nicotine Self-Administration and the Social Context

Description

Research suggests that the more positive the first drug experience, the more likely addiction will develop. Since smoking is initiated in a social setting, it is surprising how little is

Research suggests that the more positive the first drug experience, the more likely addiction will develop. Since smoking is initiated in a social setting, it is surprising how little is known about social context effects on acquisition of nicotine self-administration. We investigated this issue in rats during late adolescence using conjoined self-administration chambers that had a removable shared wall. Rats were assigned to training conditions with either a solid black plexiglass or wire mesh partition in place throughout 22 subsequent 2-hour daily training sessions. Initially, 58 day-old (late-adolescent) male and female rats received 2, 30-min habituation sessions/day over 2 consecutive days, with only an inactive lever present. Sessions began with presentation of a retractable lever and thereafter each response on that lever resulted in simultaneous delivery of saline or 1 of 2 doses of nicotine (0.015 or 0.030 mg/kg, IV) and lever retraction for a 20-second time out. The findings indicate that the social context inhibits nicotine self-administration in female rats during the development of addiction, but has little effect on the initial stages of drug acquisition. Furthermore, the data suggest that in male rats the social context enhances responding independent of nicotine, but has few effects on nicotine self-administration during the development of addiction. The findings have important implications for substance use disorders.

Contributors

Agent

Created

Date Created
  • 2015-05

136502-Thumbnail Image.png

Hepatic inflammatory response following high fat diet in adolescent male Sprague-Dawley rats

Description

There has long been a link tied between obesity and such pathological conditions as nonalcoholic fatty liver disease and type two diabetes. Studies have shown that feeding rats a diet

There has long been a link tied between obesity and such pathological conditions as nonalcoholic fatty liver disease and type two diabetes. Studies have shown that feeding rats a diet high in fat results in hepatic steatosis and steatohepatitis. Using a novel short term diet of six weeks with male adolescent Sprague-Dawley rats, our laboratory sought to investigate the early effects of high fat intake on the liver. Prior findings in our laboratory found that a high fat diet (HFD) leads to nonalcoholic fatty liver disease as well as other symptoms of metabolic syndrome. This study hypothesized that rats fed a 60% HFD for 6 weeks, unlike a high sucrose or standard chow diet, would have an elevated expression of pro-inflammatory cytokines associated with steatohepatitis. TNF-α, TLR4 and XBP1 were chosen for their link to hepatic inflammation. The results of this study found that contrary to the hypothesis, the high fat diet did not induce significant changes in the expression of any inflammatory marker in comparison to a high sucrose or control chow diet.

Contributors

Agent

Created

Date Created
  • 2015-05

135521-Thumbnail Image.png

The Importance of Art and the Creative Process

Description

Art is an inherent concept instilled in human nature, which utilizes the abilities of the creative mind to invent. Art has served many purposes in the history of mankind, including,

Art is an inherent concept instilled in human nature, which utilizes the abilities of the creative mind to invent. Art has served many purposes in the history of mankind, including, but not limited to story telling, entertainment, decoration, exploration, propaganda, education, and therapy. The primary aim of this creative project was to explore the importance of the art, as a creative process, as a way to supplement academic endeavors. The idea derived from an observation made by myself that contemporary regard for art has been on a decline, which made me question if I also value art as much as I think I do, having done art in the past and recently added a studio art minor. I thought of ways to again incorporate art and the creative process into my life. I asked myself the question: can the creative process be used as a supplement to schoolwork in order to relieve stress? To explore this, an experiment was designed, which entailed my creation of drawings twice a week, accompanied by journal documentation for a full semester of college. Afterwards, analyses were done between the documented journal entries and the artworks to see if any relationships were apparent between various aspects of my life at the times of the drawings and the drawings themselves. Further research was also conducted in related areas of study and documented in written format, which cited and analyzed numerous journal articles, artworks, artists, and research papers. This included art therapy, art education, and the relationships between art and science. Results from the experiment indicated that art as a creative process allowed for the relief of stress by cleansing my mind from any concern or interferences, therefore offering myself a complete break and relaxation, effectively refreshing my mind and allowing me to resume schoolwork or other tasks more mentally taxing. In addition, the research also showed that art therapy could effectively utilize this palliative effect of art making to ease the problems of people in distress. The findings also concluded that art and science go hand in hand, which explains a lot of the similarities in methodologies utilized by scientists and artists. In conclusion, art is a paramount part of mankind in exercising the creative mind and is ubiquitous; we should learn to actively embrace it to enrich our lives.

Contributors

Agent

Created

Date Created
  • 2016-05