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2008 Research Abstracts Adesuwa Aighewi , University of Maryland, Eastern Shore The majority of studies on the movement of living or once-living materials through the atmosphere have focused on insect pest species. Over the past 10 years however, these studies have expanded to include investigations of the movement of fungal spores and pollen through the atmosphere, and a few have focused on bacterial species present in the air that we breathe. In this study, air samples were collected from February to August of 2007on a biweekly basis, with a sampling filter apparatus was stationed on the South Main campus of Howard University in Washington, DC. The filter samples were collected mid week for a twelve-hour period beginning at 7:00 AM and concluding at 7:00 PM. Screening and analysis all 16S rDNA bacteria isolates was performed by cultural methods. The isolates were subjected to the standard antibiotic susceptibility and resistant testing. A total of 52 isolates were identified to two Gram positive bacterial genera; Bacillus and Enterococcus from a total of 76 isolates. Gram positive organisms have the potential to cause community acquired pneumonias. Based upon molecular analysis, it is suggestive that the species within the genera are new species. The distributions of the isolates are as follows: Bacillus 51; and Enterococcus 1. 23 were Susceptable to Ampicillin, Penicillin (15), Erythromycin (31), Ciprofloxin(42). In addition, 35 microbials were resistant to Ampicillin, Ciprofloxin, Doxycycylin, Penicillin and Erythromycin. 15 isolates were in the intermediate resistance category for these antibiotic treatment. The antibiotics tested are standard treated for diseases causes by these bacterial species. Although the isolates were not analyzed for possible virulence factors, the results provide critical insight of microbial biodiversity in the Washington DC, Metro Area, and the need to revise medical therapy and the development of new antibiotics to fight this family of possible new microorganisms. These microorganisms tested, have the potential for impacts on human respiratory health as well as other human disease conditions. Crystal Brickhouse, Spelman College For my research project, I will be looking at the polymorphism of five malaria drugs. Polymorphs are molecular solids usually arranged in a crystalline lattice, and these solids will diffract X-rays with a unique pattern specific to a certain molecule. A single molecule can potentially crystallize into a number of different packing arrangements with different stabilities and melting points in their crystalline forms. Bioavailability actually measures the quantity of a drug in the blood plasma and the time over which a drug is absorbed in the GI tract is know as the “window of absorption”. Since different polymorphs of a drug possess different solubility and dissolution time curves they can have different bioavailability. The control of the polymorphic form of drug molecules is important to ensure reliable and bioavailability of drugs delivered to the patient. We are characterizing the crystallization behavior and range of crystalline polymorphs available for these drugs. I will analyze my results through X-ray powder diffraction, melting point, and Infared (IR) analysis. Ultimately, my research will be transferred to manufacturers of malaria drugs in India and China through the Clinton Health Care Access Initiative. Evelena Cousin, Howard University An association between alcohol consumption and prostate cancer is not well-understood. Several studies suggest that there is not a correlation with alcohol use and prostate cancer risk while others indicate that high alcohol consumption and/or particular alcohol types may promote an increase risk in prostate cancer incidence. In addition to determining whether alcohol consumption plays a role in prostate cancer occurrence, it is also important to understand the effects of alcohol on prostate cancer cell signaling events. This study examined whether alcohol induces activation of key cell survival signaling proteins, AKT and ERK 1/2, in prostate cancer cells. Activation of these signaling proteins promotes cell survival by inhibiting programmed cell death, apoptosis. LNCap and DU145 prostate cancer cell lines were used in these examinations. Cells were incubated with physiological relevant alcohol concentration of 20mM for 15 minutes, 30 minutes, 1 hour, 6 hours, 12 hours, and 24 hours. Epidermal Growth Factor (EGF) at 10ng/ml was used as a control stimulant because of its reproducible stimulation of AKT and ERK 1/2 activation. After each time point, the media without or with alcohol or EGF was removed and the cells were collected for further western blot and apoptosis analysis. Our results indicate that incubating physiological relevant alcohol concentrations with prostate cancer cells for short time periods, between 5 minutes and 1 hour, did not produce an affect on AKT and ERK1/2 activation, whereas incubation times greater than one hour promoted activation of AKT and ERK 1/2. The increase in activities of AKT and ERK1/2 as a consequence of alcohol incubation coincides with a subsequent decrease in the number of prostate cancer cells undergoing programmed cell death, apoptosis. This suggests that long exposure periods of prostate cancer cells to alcohol can be detrimental by enhancing cancer cell survival. This study demonstrates at a cellular level signaling pathways AKT and ERK 1/2 in prostate cancer cells are affected by alcohol exposure. These results indicate that a more effective treatment for patients suffering from alcoholism and prostate cancer may be combination therapy that incorporates targeting of these signaling pathways. Lauren DeBerry, Howard University The majority of studies on the movement of living or once-living materials through the atmosphere have focused on insect pest species. Over the past 10 years however, these studies have expanded to include investigations of the movement of fungal spores and pollen through the atmosphere, and a few have focused on bacterial species present in the air that we breathe. In this study, air samples were collected from February to August of 2007on a biweekly basis, with a sampling filter apparatus was stationed on the South Main campus of Howard University in Washington, DC. The filter samples were collected mid week for a twelve-hour period beginning at 7:00 AM and concluding at 7:00 PM. Screening and analysis all 16S rDNA bacteria isolates was performed by cultural methods. The isolates were subjected to the standard antibiotic susceptibility and resistant testing. A total of 24 isolates were identified to six Gram negative bacterial genera. Gram negative organisms have the potential to become pathogenic and cause disease. Based upon molecular analysis, it is suggestive that the species within the genera are new species. The distributions of the isolates are as follows: Enterobacter 11; Yesinia 3; Escherichia 4; Pseudomonas 2; Pantoea 4; 8 were resistant to Ampicillin, 1 was resistant to Gentomicin, 5 were resistant to Penicillin. Additionally, 4 microbials were found to be Intermediate to the antibiotics Ciprofloxacin, Tetracline, Erythrmycin, and Penicillin. The antibiotics tested are standard treated for diseases causes by these bacterial species. Although the isolates were not analyzed for possible virulence factors, the results provide critical insight of microbial biodiversity in the Washington DC, Metro Area, and the need to revise medical therapy and the development of new antibiotics to fight this family of possible new microorganisms. These microorganisms tested, have the potential for impacts on human respiratory health as well as other human disease conditions. Bette Ford, University of West Georgia Synthesizing HIV Drugs, Specifically Ritonavir, to Make Them More Cost Efficient Ritonavir and lopinavir (RTV and LPV) are essential drugs used to treat symptomatic HIV/AIDS. In 1996, Ritonavir was approved by the US FDA to control the outbreak of HIV/AIDS victims. These drugs belong to a particular class of medicines known as Protease Inhibitors (PIs). These inhibitors prevent the replication of HIV viral RNA by inhibition of the HIV-Protease enzyme. This enzyme is significant due to its critical impact on the lifecycle of HIV virus. In relation, ritonavir has an important secondary effect on human metabolism. All of the HIV drugs of the Protease Inhibitor class are primarily metabolized by Cytochrome P450 Oxidase 3A4 isozyme. Therefore, patients taking ritonavir co-dosed with RTV in combination of other Protease Inhibitors show higher blood levels of the “other PI” than in the absence of RTV. This is a critical advantage in that a number of other PI drugs would be ineffective in treating AIDS without the addition of RTV. With the steady increase of HIV/AIDS victims and essential cost to provide treatment to emerging nations, there is a crucial need to reduce the cost of Active Pharmaceutical Ingredients (APIs) that are critical for treatment. By acquiring the correct chemistry of the improved compound, we hope to reduce the cost of these APIs form roughly $1000/kg to the range of $500/kg. Hopefully, by reducing the cost, we can help save lives in countries that are unable to afford proper treatment. Benedict Ifedi, University of Houston Tracing Brain Pathways: Mapping the Neurons that Make the Eyes Work By the process of retrograde, trans-neuronal tracing with a genetically engineered pseudorabies virus (PRV), our goal is to construct a detailed map outlining the extensive network of nerves that function to make the eyes work. PRV is one of only a few tracers that will cross synapses in the “backwards” direction, allowing us to inject the agent in the peripheral muscles and follow the sequence of neural connections back into the brain. One variation of the PRV used to track the location of neurons expresses green fluorescent protein (GFP), while the other expresses red fluorescent protein (RFP); both serve as markers used to identify the location of neurons related to eye functionality. Tracing the neuronal pathways linked to oculomotor function will allow us to develop a better understanding for the basis of the behavior exhibited by the activity and movement of the eyes. Funded by NIH Grants NS-U54-039407, EY-R01-15870 and EY-R03-08217. Anwar Jackson, Howard University The Effects of Exercise on Factors Associated with Prostate Cancer Literature has shown that physical activity may lead to lower incidence of prostate cancer. Studies have also shown that blood serum levels of insulin-like growth factor binding protein-3 (IGFBP-3) may have an inverse relationship with the incidence of prostate cancer. The purpose of our study was to explore the effects of aerobic and anaerobic physical activity on both blood serum levels (IGFBP-3) and prostate cancer cell growth in young African-American men. We hypothesized that exercise-altered serum would have higher levels of IGFBP-3 and support less LNCaP cell growth than pre-exercise serum. Nineteen African-American men between the ages of 20 and 25 were randomly chosen to undergo either seven consecutive days of aerobic exercise (n = 7), seven consecutive days of resistance training (n=7), or seven consecutive days of no exercise regimen (n=5; these men were in the control group). Serum was extracted from each patient before and after the seven days of physical activity, and both the pre-activity and post-activity serum samples from each patient were tested for IGFBP-3 expression and prostate cancer cell (LNCaP) growth in vitro. No significant changes in IGFBP-3 expression were observed in the aerobic exercise (p=0.135) and control (p=0.156) groups, but the resistance training group (p=.0139) experienced a significant increase in IGFBP-3 expression between the pre-exercise and post-exercise serum. This data suggests that resistance training may have a significant role and increasing the blood serum levels of IGFBP-3. While there was no significant change in LNCaP cell growth from pre-exercise serum to post exercise serum for all groups (p=0.486 for aerobic exercise, p=0.145 for resistance training, p=0.196 for control), the results suggest that if this experiment was repeated with a larger sample size, significant changes may occur in both the aerobic and resistance exercise groups. Brittany Jelks, Alabama A&M University Racial Differences in Men's Perceptions of Interracial Domestic Abuse Cases The present study examined racial differences in men’s perceptions of an interracial domestic abuse case. Forty-eight male college students from Howard University and the University of Kansas, were asked to read one of four versions of an interracial domestic abuse case. They were asked to respond to several open-ended questions, which measured their perceptions of the case. Results showed that White and Black men’s perceptions of the situational causes of the incidents, dispositions they attributed to the defendant, and dispositions they attributed to the victim differed significantly as a function of the defendant’s race. Ke’Andrea Kelly, Alcorn State University The majority of studies on the movement of living or once-living materials through the atmosphere have focused on insect pest species. Over the past 10 years however, these studies have expanded to include investigations of the movement of fungal spores and pollen through the atmosphere, and a few have focused on bacterial species present in the air that we breathe. Gram positive organisms from an environmental aspect can be harmless or cause harm to humans, plants, and agriculture life. Gram negative organisms can cause disease when they become pathogenic. They also play a significant role in nitrogen fixation. In this study, previously collected bi-weekly air samples from August 2007 through January 2008, with a sampling filter apparatus stationed on the South Main campus of Howard University in Washington, DC., were screened and analysis all 16S rDNA bacteria isolates was performed by cultural methods. Climatic screening and weather analysis was observed and recorded. A total of three hundred and sixty two bacterial isolates cell walls were identified to three hundred and thirty four Gram positive microbials, and 28 Gram negative microbials. The presence of a very high Gram positive population is suggestive of methylcillan resistant organisms and community acquired pneumonias that are occurring in the urban communities. The presence of Gram positive organisms frequently appeared during the high temperature seasons, and well as the low seasons. However, the presence of Gram negative organisms appeared during the high temperature and humid conditions. Although the isolates were not analyzed for possible virulence factors, they were analyzed for antibiotic resistance. The results provide critical insight of microbial biodiversity in the Washington DC, Metro Area. The microorganisms identified, have the potential for impacts on humans, plants, and agricultural life as well as other human and animal disease conditions. Lauren Roach, Alcorn State University The Influence of Elevated Plasma Thyroxine on Olfactory Bulb Retinoid Receptors and Neurotrophins Recent findings in our laboratory observed that in adult mice that were given 0.003% thyroxine (T4) in their drinking water for fourteen days, there was a significant increase in the number of neuronal precursors in the olfactory bulb (OB) and a decrease in glial fibrillary acidic protein (GFAP), a neurotrophin. Several studies indicate that retinoic acid is a key regulator in postnatal adult neurogenesis in the OB. Retinoic acid (RA) is a lipophilic molecule synthesized from Vitamin A that functions to control gene expression, is particularly active in transcription, and plays an important role in the development and maintenance of the nervous system. The presence of retinoid binding proteins and RA receptors (RARs) is of great interest because the heterodimeric partnering between RARs and thyroid hormone receptors (TRs) suggests that a change in circulating thyroid hormone (TH) concentration could potentially impact neurogenesis. We further investigated the effect of the short term elevation of T4 levels on RARs and neurotrophins in the OB of these mice. Western Blot analysis of the OB tissue revealed that there was a statistically significant, 44% decrease in RARβ expression in the treated animals. We further mapped the immunophenotypes of various retinoid receptors, doublecortin, GFAP, tyrosine hydroxylase, and other OB cellular markers in response to the elevated T4 status. Our results indicate that altered thyroid hormone levels may have a profound impact upon retinoid signaling in adult neuronal tissue. Jose Saltos, College of Staten Island Antidepressant-Like Effects Of Ketamine In An Animal Model Of Depression Although various pharmacological therapies for the treatment of depression are available, their delay in onset, side effects and lack or response is of major concern. Thus, there is a need for development of more effective medication. Ketamine has been used as a anesthetic, particularly in veterinary medicine. Recent preclinical as well as clinical evidence support a rather quick onset of an antidepressant effect following acute administration of ketamine. Moreover, the antidepressant effects of ketamine appear to be long lasting. In this study, we sought to determine the dose-response and the duration of action following acute administration of ketamine in a rat model of depression. Wistar-Kyoto (WKY) rats exhibit significant immobility in the forced swim test (FST), reflective of their helplessness and depressive-like behavior. Acute intraperitoneal (IP) administration of ketamine at doses of 2.5 and 5.0 mg/kg resulted in a reduction of immobility in FST in WKY rats only. The effect of 5.0 but not 2.5 mg/kg ketamine was still evident after one week. The results of this study confirm a rapid and lasting antidepressant-like effect of relatively low ketamine dose in WKY rat model of depression. Although more studies are needed the results of the current experiments suggest that ketamine or drugs with similar mechanism of action may have beneficial effects in treatment of depression. Makina Table, Howard University Nanoparticle Encapsulated Biodegradable Polymeric Implant for Bone Tissue Engineering Conventional treatment of osteomyelitis involves surgical intervention of dead bone tissue and systemic administration of antibiotics. The primary objective of the study is to develop antibiotic containing biodegradable polymeric implants that support bone tissue growth and minimizes infection. Many new polymers and polymeric composites have been assayed for a broad range of applications including drug delivery and tissue engineering. One polymer in particular that has drawn considerable attention for bone tissue formation is poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). In this study, an attempt was made to encapsulate nanoparticles (gentamicin or silver) in PHBV matrix and study the drug release rates. The selection of the nanoparticles was based on well established antimicrobial characteristics. Gentamicin release in phosphate buffer (pH 7.4) solution was quantified by reacting with ninhydrin and recording the absorbance of the solutions at 400nm. Silver nanoparticle was quantified by acid digestion followed by atomic absorption analysis. Details pertaining to the encapsulation protocol and preliminary release rate information of nanoparticles from the PHBV matrix will be presented. Sonia Taneja, University of Virginia An absence of the normal “dip” of blood pressure at night is an established risk factor for hypertension and its end-organ complications, and “non-dipping” of nocturnal blood pressure is more prevalent in African Americans compared with Americans of European descent. Certain cardiovascular risk factors are hypothesized to contribute to non-dipping, including being overweight, living a sedentary lifestyle, and exhibiting negative emotional responses to stressors, such as experiencing racism. Dr. Mellman and colleagues found a strong correlation between symptoms of posttraumatic stress disorder (PTSD) and non-dipping of nocturnal blood pressure, and interestingly, sustained non-dipping was found even in the lifetime, or PTSD remitted group, as well. This experiment is designed to evaluate factors contributing to continued non-dipping in PTSD remitted participants. After Dr. the research group administered surveys, tabulations of each risk factor were recorded in addition to participants’ PTSD diagnoses, and if at least a ten percent dip in blood pressure was observed during sleep, the participant would be categorized as a “dipper”. Out of 30 participants, 11 were diagnosed as having subthreshold or full lifetime PTSD, but did not have current PTSD. Of those 11, 7 were non-dippers. Of those non-dippers, 3 were overweight, 3 were categorized as engaging in low physical activity during a typical week, and another 3 displayed at least a moderately negative emotional response to racism. The entire group displayed at least one risk factor, with two participants displaying two. Of the 4 dippers, none were overweight, only one engaged in low physical activity, but all four displayed at least a moderately negative emotional response to racism. Thus, the entire group displayed at least one risk factor, with one displaying two. The conclusion was that low physical activity and weight gain could contribute to non-dipping, however the data used in this study is preliminary and the influence of such risk factors must be explored further and on a larger scale. Kayla Thomas, Biola University Protective Effects of Low Alcohol Concentrations Against Salsolinol-Induced Toxicity Salsolinol is an endogenous compound that is formed from the condensation of dopamine and acetaldehyde. Dopamine is an important neurotransmitter, deficiency of which may lead to Parkinson’s disease (PD). PD is a neurodegenerative disorder characterized by tremors, muscle rigidity and slow movement. Although the cause of PD is not established, it is believed that degeneration of dopaminergic cells in the substantia nigra is the primary pathology associated with PD. It has been shown that high levels of salsolinol may be toxic to dopaminergic neurons. Since acetaldehyde is a major metabolite of alcohol it may be expected that high consumption of alcohol may lead to higher salsolinol levels and hence toxicity to dopaminergic neurons. However, low alcohol levels may have neuroprotective effects. In this study we sought to determine whether low alcohol concentration may protect against salsolinol-induced toxicity. SH-SY5Y cells derived form human neuroblastoma, are used as a model of substantia nigra dopaminergic cells. Thus, these cells were exposed to toxic levels of salsolinol with and without pretreatment with various concentrations of ethanol. It was found that pretreatment of SH-SY5Y cells with low concentrations of ethanol (1 and 10mM) had protective effects against salsolinol-induced toxicity as determined by the MTT assay. Although in-vivo verification of these findings is necessary, it may be concluded that low alcohol consumption may have protective effects in neurodegenerative disorders such as PD. Leandria Thomas, Xavier University The Role of Growth Factor Proteins in Cardiac Hypertrophy Observed in Neonatal Cardiomyocytes Cardiac hypertrophy leading to apoptosis has been a major impediment to the treatment and preventative measures against heart failure. To combat its negative effects, the likely key signaling pathways were studied in greater detail. To understand those pathways, different combinations of growth factors were observed in neonatal cardiomyocytes to determine level of protein activity. Our data suggest that IGF-1 increased the activity of Akt in a dose dependant manner, Adenoviral transfection with Ad-Akt does not increase the activity and that PI 3K, enhances the Akt activity. Angelica R. White, Alcorn State University The Gene Expression of Growth Factor Proteins as Indices of Cardiac Hypertrophy versus Apoptosis Cardiac hypertrophy is the cellular response to an increase in biomechanical stress. It represents the initial stage in a number of cardiac diseases that can progress to heart failure. Using the Neonatal Cardiomyocyte Isolation System, rat pups’ heart cells were isolated. Following isolation, cells were incubated in a culture medium with FBS for 24 hours. Once drugs/ viruses are added to 12 samples, RNA was extracted using the Aurum Total RNA Fatty and Fibrous Tissue Kit. Total RNA was reverse transcribed and then amplified by the polymerase chain reaction using a Super Script Preamplification System for cDNA Synthesis and Taq DNA polymerase. As a result of my data, I can conclude that TNF-α has both an anti-apoptotic and hypertrophic effects; which are enhanced in the presence of IGF-1, but circumvented by EGF. It is also noted that IGF-1 reverses ANG II apoptotic effect as well as enhances its hypertrophic effect. However, EGF hypertrophic effect is masked in the presence of TNF-α and ANG II. Fabian Wiley Jr., Alcorn State University Eukaryotic cells are known to utilize scaffold proteins to integrate multiple signals through organized proximity of signaling components. In addition, scaffold proteins are emerging as essential spatial and temporal regulators of signal transduction networks. One family of scaffold/anchoring proteins, Receptor of Activated Protein Kinase C (RACK), is widely thought to play a central role in critical biological processes. The study of RACK1-mediated signaling pathways in non-plant organisms continues to be an exciting and growing research field; however, cellular functions of the highly conserved plant RACK1 proteins remain to be determined. Gene knock-out in rack1a implicate the protein in diverse environmental stresses including hypoxia signaling pathway. Current projects in the lab are mainly geared to elucidate the cellular function of RACK1A gene that is found to regulate diverse environmental stress responses. My project will aim to molecularly dissect the role of RACK1 protein gene expressions play in regulating diverse stress signal transduction pathways. Information on the tissue specific expression of all three RACK1 proteins in response to stresses like drought, oxidative, hypoxia will certainly help understand the signaling pathway better. Elucidating the role of RACK1 proteins in these stress signaling pathway will help in bioengineering of environmental stress resistant crops in future. |
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