Division I

  Abstracts Submitted: Division I - Undergraduate students - Biomedical Sciences


COMPARISON STUDY OF THE PHARMACOKINETICS OF DIFFERENT FORMS OF DRUGS

Leena Amine, Department of Chemistry, East Tennessee State University, Johnson City, TN 37614

There are many forms of drugs available for people today. These forms range from tablets to patches, but each individual form has its own route of administration and is taken up differently by the body. In this comparison study, the pharmacokinetics and routes of administration of different forms of drugs were compared and studied. The pharmacokinetics of drug processes deals with the absorption, distribution, metabolism, and excretion of drugs in the body. The form of the drug determines its route of administration, and the route of administration in turn affects the bioavailability of the drug. Bioavailability of a drug is the percentage of the dose of a drug that is actually absorbed into the blood stream (Hitner and Nagle 24). Therefore, to be able to study the efficacy and pharmacokinetics of certain drugs, their forms must be studied and designed carefully to maximize effectiveness. In this comparison study, tablets, enteric-coated tablets, timed-release capsules, orally administered liquid medicines, parenterally administered liquids, topical sprays and ointments, patches, and aerosols and gases were studied and compared with respect to their route of administration and pharmacokinetics. The similarities, as well as the differences, were examined given respect to efficacy, and chances of improvement and predictions about drug trends were made. An observation into the development of drug forms today revealed an increasing trend in convenience in designing new ways of administering drugs. Making drugs more favorable to the patient’s comfort and needs were especially observed in the mechanisms of both the timed-release capsule and the birth control patch. Also, a suggestion for making painkillers more effective and convenient by formulating them into sublingually administered tablets was made.


VITAMIN E MEDIATED CELL DEATH IN COLON CANCER CELL LINE HCT-15 IS PEROXISOME PROLIFERATOR ACTIVATED RECEPTOR (PPAR) DEPENDENT

Paige Goforth, Sarah Whaley and Sharon Campbell, Deparment of Biological Sciences and Internal Medicine, East Tennessee State University, College of Medicine, Johnson City, TN 37614

Mediterranean societies, with diets rich in vitamin E isoforms, have a lower risk for colon cancer than those of northern Europe and the Americas (Khlat, 1995).  In addition, diets rich in antioxidants including vitamin E have protective effects against cancer (Slattery, 1995 and Patterson, 1995) .    The term Vitamin E represents eight structurally-related compounds.  The vitamin E isoform found primarily in the US diet is gamma-tocopherol, while alpha-tocopherol is the isoform highest in the plasma.  Vitamin E rich diets may neutralize free radicals generated by fecal bacteria in the gut and prevent DNA damage, but there is increasing evidence that vitamin E, in particular, gamma-tocopherol,  has regulatory effects that are antioxidant independent.  Vitamin E isoforms share structural similarity to the thiazolidine drugs which are known PPAR ligands.  PPARs are ligand-activated nuclear receptors that regulate gene expression through DNA binding. Ligand activation of PPAR gamma results in growth inhibition, differentiation, and apoptosis in a number of different cancer cells including, colon (Kitamura, 1999).  This study was designed to test the hypothesis that Vitamin E isoforms could modulate PPAR expression resulting in significant cell death in the human colon cancer cell line, HCT-15.  HCT-15 were treated in the presence or absence of alpha or gamma-tocopherol for varying time intervals.  Cell counts over time were collected using the trypan blue assay and hemocytometer counting.  RT (Real Time)-PCR using the SYBR-green method monitored the expression of the PPAR gamma and delta transcripts. Western blot analyses were used to monitor the expression of PPAR gamma and delta proteins.  To determine if the reduction in cell growth was PPAR gamma dependent, cell counts following the tocopherol treatment in the presence or absence of the PPAR gamma antagonist GW9662 were performed.  The data show that gamma-tocopherol results in significant cell death while alpha-tocopherol does not.  PPAR gamma mRNA and protein expression increase in the presence of tocopherol treatment, while PPAR delta expression decreases compared to untreated cells.  Further, blocking the PPAR gamma pathway with GW9662, results in cell rescue, suggesting that gamma-tocopherol modulates cell death through a PPAR-dependent pathway. 


Cellular Chemoprotective Effects of Flavone, the Simplest Dietary Flavonoid

Joseph Falcone and Phillip Musich, Department of Biochemistry & Molecular Biology, J. H. Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614

A healthy diet reduces certain cancers. Could phytochemicals which normally protect plants against UV radiation also protect non-plant organisms, especially humans? Oxidative and UV damage can cause DNA nicks (breaks) and base modifications, and/or cause cross-linking between adjacent thymine bases, respectively. This damage may cause mutations (a pro-mutagenic effect). Flavonoids are found in fruits and vegetables, and also in chocolate, wine and tea. This study measured the ability of flavone, the simplest flavonoid, to protect DNA against oxidant- and UV-induced mutations using multiple assay systems. In the first assay plasmid DNA containing an ampicillin resistance gene was exposed to hydroxyl radicals with/without added flavone before transformation into E. coli cells. Plasmid integrity was tested by measuring cell viability on ampicillin-containing plates. Flavone at 7.5 mM showed the highest protection against oxidative damage. In a cellular UV-damage assay flavone was added to E. coli cells containing a tetracycline resistance plasmid. The cells were exposed to UV light and plasmid and cellular functionality measured by growth on tetracycline-containing agar plates. Flavone at 2.5 mM demonstrated the highest protection against UV damage, whereas 5.0-7.5 mM flavone inhibited cell growth. To test for a metabolic protective effect E. coli cells able to grow in the 5.0-7.5 mM flavone were isolated. These flavone-tolerant cells exhibited a greater reduction in UV mutations at 5.0-7.5 mM than at 2.5 mM flavone. Together these data demonstrate that flavone affords protection against both oxidative- and UV-induced DNA and cellular damage, both as a sunscreen and as a metabolite. These data show the protective effect of flavone in bacterial cells, and raise the question of whether flavone also may protect eukaryotic cells, especially human skin cells that experience significant UV radiation. Skin cancer is becoming the most common type of cancer, with more than 700,000 cases of non-melanoma skin cancers (NMSC) diagnosed yearly in the United States.  The main cause of NMSC is solar UV radiation.  Studies have been initiated to investigate whether flavone also protects human cells against UV damage both as a non-metabolic agent (i.e. a sun screen effect) and via a metabolic effect within the cells.  Human skin cells (GM006375) are cultured in 96-well microtiter plates and cell integrity monitored using two assays.  The first is a cell proliferation assay which measures the functionality of mitochondria in metabolically active cells.  If cell growth rate is reduced and/or cells death occurs due to the flavone and/or the UV treatments, a reduction in mitochondria function will be recorded.  The second assay monitors membrane integrity via the release of lactate dehydrogenase (LDH) from treated cells; LDH release would indicate membrane damage caused be UV light.  Initial studies indicate that flavone concentrations over1 mM are toxic but not at 75 ìM or less.  Although, the human cells are more sensitive than the E. coli cells, these data indicate that flavone may be a beneficial additive to sunscreens and/or as a nutrition supplement for protection against the suns damaging rays.


ENHANCING EFFECTS OF EPINEPHRINE ON PRO-ATHEROGENIC CHEMOKINE PRODUCTION IN IL-1β-ACTIVATED MAST CELLS

Amanda G. Mullins, Karen Cantor, Kenton Hall, Guha Krishnaswamy, David S. Chi.  Department of Internal Medicine, East Tennessee State University, College of Medicine, Johnson City, TN, 37614

Atherosclerosis causes cardiovascular disease (CVD).  Present within the atherosclerotic lesions are large numbers of mast cells.  Stress has previously been shown to elevate catecholamine (Cate) levels and contribute to the development of CVD.  Recently, we have shown that catecholamines such as epinephrine enhance the production of pro-inflammatory chemokines in IL-1β-activated human mast cells (HMC-1).  Here we study the effects of epinephrine on production of pro-atherogenic chemokines (IL-8, MCP-1¸ and RANTES ) and monocyte chemotaxis in the supernatant of Cate and IL-1β-activated mast cells.  Two mL of HMC-1 (0.75 x 10 6 cells/mL) were cultured with epinephrine (Epi, 1.0 x 10 -5 M) in the presence or absence of IL-1β (10 ng/mL) for 24 hrs.  In some cultures, the antagonists, propranolol (Pro, 1.0 x 10 -4 M) and atenolol (Ate, 1.0 x 10 -4 M), were also added.  The supernatants were measured for chemokines by ELISA, and for monocyte chemotactic activity using a NeuroProbe chemotaxis chamber.  RANTES production ranged from  undetectable to trace.  Epi alone did not induce significant production of IL-8 or MCP-1 in HMC-1.  When Epi was added to IL-1β-activated-HMC-1, the production of IL-8 and MCP-1 was enhanced significantly (p < 0.02).  Pro significantly reduced the enhancing effect of Epi on IL-8 and MCP-1 production (p < 0.02), but Ate did not.  The chemotactic activity was increased in the supernatant from the IL-1β plus Epi-activated HMC-1 cultures, but was not significant.  Results indicate that Epi enhanced the production of pro-atherogenic chemokines from mast cells and provide a novel role for Cate in inflammation and atherogenesis.  (Supported by NIH grant HL 63070, the RDC and Honor Prog. of ETSU)

A Study to Review the Trends in Maternal Drug abuse During Pregnancy in Northeast Tennessee.

Martine Nkurunziza, East Tennessee State University, Department of Chemistry, Johnson City, TN, 37614

Maternal drug abuse can be very harmful for the mother and the unborn child. There is a big variety of drugs available for pregnant women, from prescribed medications to illicit drugs that can harm the mother or the unborn baby. This study was conducted on women who delivered infants at a local hospital in the year 2003 with a documented illicit drug use. The objective of the study was to review the trend in maternal drug abuse during pregnancy. The study was conducted by reviewing charts of children and their mothers. The most common drugs were marijuana, methadone and cocaine. The percentage of women who used illicit drug during pregnancy was 5.43, with 80% under 30 years old. Maternal screening for drug was positive in 65% while infant screening was positive in 38% of those tested. 36 % had a cesarean delivery and 46% had premature babies.18 % had NAS (Neonatal Abstinence Syndrome), and among babies who had NAS, 69% of them had been exposed to methadone. While marijuana was the most used drug, methadone was the most associated with NAS.


What Do Hispanic Woman Receiving Prenatal Care Know About Preterm Labor?

Melissa Hinton, East Tennessee State University, Department of Family and Community Nursing, Johnson City, TN 37614

Even though the problems of preterm labor have been identified and the options for treatment have been expanded and made more available, the rates of preterm birth and infants born prematurely are still rising. Prevention of preterm labor by focused patient education may be one approach to improving this problem. This descriptive pilot study investigates the knowledge of Hispanic women who are receiving prenatal care at an area clinic regarding preterm labor, infant prematurity, and prenatal care before and after an individual focused teaching session. Five Hispanic women ranging from 14 to 34 weeks gestation and 17 to 30 years-old participated in this study. Participants answered a personal health survey and completed a pretest using a 10-question tool to evaluate baseline knowledge concerning preterm birth which was developed by Margaret Comerford Freda, RN, EdD, CHES, in 1991 with validity established by registered nurses and certified nurse midwives and a test-retest reliability established(r=0.95). Following the pretest, the women participated in a focused teaching session which addressed the definition of preterm labor, the length of normal and preterm pregnancies, possible health risks facing preterm or premature infants, possible causes and factors that increase one’s risk for preterm labor, symptoms or warning signs of preterm labor, actions to take in response, and health habits to help prevent preterm labor. The participants finally completed a posttest using the same tool to evaluate knowledge after the focused teaching session. Descriptive data analysis of the pretest indicated several areas in which the majority of women answered incorrectly or indicated they did not know the answers to the questions including the synonymous meanings of “preterm” and “premature,” potential health problems facing infants born preterm, identifying a symptom of preterm labor, and the possibility of experiencing preterm labor symptoms while doing heavy housework. All of the participants answered more questions corr....