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Pellissippi State Technical Community College Knoxville, Tennessee. (Eastern Region).

YEAST MATING RECEPTORS ARE SENSITIVE TO ANTIFUNGAL AGENTS. Sebastien Demoiny, Drew Reynolds, and Stephen Wright, Carson-Newman College, Jefferson City, Tennessee. Alpha-factor is an external signaling molecule that binds to the surface of yeast cells and signals the production of proteins within the cell involved in the mating response. The receptor that binds [alpha]-factor is similar to the most abundant group of receptors in mammals. Using brewers yeast, Saccharomyces cerevisiae, we studied the activity of the membrane receptor after the cells were treated with the anti-fungal drug ketoconazole. This drug reduces the levels of sterols in the membrane by inhibiting their synthesis. Using an assay where we could measure the ultimate effects of receptor activation on gene activity, we found that total receptor activity was reduced in the presence of the drug even at high concentrations of [alpha]-factor. These findings lead us to believe that the drugs may reduce the number of receptors or change the membrane lipids so that the receptors are disabled.

THE ANTIFUNGAL DRUG DIFLUCAN ALTERS THE ACTIVITY OF A CELL SURFACE RECEPTOR. Drew Reynolds, Sebastien Demoiny, and Stephen Wright, Carson-Newman College, Jefferson City, Tennessee. We examined the effects of the antifungal drug Diflucan on the growth and pheromone response in the yeast Saccharomyces cerevisiae. Pheromones are released from yeast cells to signal the mating response with yeast of another mating type. The pheromone [alpha]-factor binds to a cell surface receptor that then activates many proteins within the cell and eventually turns on genes that allow the cells to fuse. One of theses genes has had a marker gene fused to it so these events may be quantified. Diflucan is a drug that inhibits growth of yeast cells by changing the levels of sterols in the membrane where the receptor is located. We found that the drug significantly reduced the level of receptor activity as determined by the gene activation assay. The affinity of [alpha]-factor for the receptor does not seem to be as strongly affected as the total activity.

THE ACCURACY OF THE GRAVITATIONAL FLOTATION TECHNIQUE USING ZINC SULFATE FOR DETECTING GIARDIA DUODENALIS CYSTS IN FECES. Wendy L. Lane, Charles Faulkner, and Sharon Patton, Pellissippi State Technical Community College, Knoxville, Tennessee, and The University of Tennessee School of Veterinary Medicine, Knoxville, Tennessee. A direct comparison of the centrifugal and gravitational flotation techniques, using Zinc Sulfate (ZSF), for the detection of Giardia duodenalis cysts in feces was accessed. The purpose of this experiment was to: 1) determine the practicality and diagnostic accuracy of detecting the protozoan Giardia duodenalis using gravitational techniques in the context of daily veterinary practice, 2) determine the adequacy of ZSF as a reliable flotation medium that does not extensively compromise and distort the integrity of the cysts when the gravitational flotation technique is allowed to incubate for 10, 15, and 20 min respectively, and 3) to discover the optimal incubation period for diagnostic purposes. The data observed and recorded strongly suggest that the gravitational fecal flotation technique is extremely inferior in kind to the centrifugal flotation technique, recovering only 10% of the cysts that were recovered from the centrifugal method.

TREATMENT OF HYDROGEN CYANIDE AND HYDROGEN CHLORIDE INHALATION IN MICE WITH HYPERBARIC OXYGEN THERAPY VERSUS SUPPLEMENTAL OXYGEN. Renee Rader, Southern Adventist University, Collegedale, Tennessee. Hyperbaric oxygen (HBO) therapy promotes faster tissue healing by increasing the amount of oxygen carried to the tissues. HBO is currently used to treat carbon monoxide poisoning as well as smoke inhalation. Based on this information, it is believed that HBO will promote faster healing for hydrogen cyanide gas or hydrogen chloride gas inhalation, which are encountered in burning material. To test this theory, mice were exposed to HCN or HCl gas. The mice were then placed in hyperbaric oxygen or given supplemental oxygen. Weight change and overall survival rate were used to establish what method of treatment promoted the fastest healing after gas exposure. It was determined that mice treated with supplemental oxygen alone healed as quickly as those treated with hyperbaric oxygen. Therefore, in the case of hydrogen c yanide or hydrogen chloride inhalation, supplemental oxygen alone is the preferred treatment.

POLYMER QUANTUM DOTS: EVIDENCE FOR A NANOCRYSTALLINE PHASE OF A SEMICONDUCTING POLYMER. Pradeep Kumar, Mark Dadmun, Adosh Mehta, and Michael D. Barnes, University of Tennessee, Knoxville, Knoxville, Tennessee, and Chemical Sciences Division of Oak Ridge National Laboratory, Oak Ridge, Tennessee. The optoelectronic and luminescent properties of MEH-PPV, a well-known semiconducting polymer, has made it the material of choice in a number of research and development directions aimed at engineering polymer-based low-threshold microlasers, light-emitting diodes, and other photonics applications. The chain configuration and chromophore alignment, probed extensively in thin films, are important parameters in determining the performance of these devices. Here we discuss novel probes of polymer chain organization and chromophore alignment of isolated MEH-PPV nanoparticles using Atomic Force Microscopy (AFM) and fluorescence emission pattern imaging. The results show that the polymer chains are highly organized in a rod shaped nanoparticle whose long axis can be uniformly oriented perpendicular to a glass substrate. This has important implications for nanoscale photonics and microlaser applications.

UTILIZATION OF OPTICAL TWEEZERS FOR THE TRAPPING AND MANIPULATION OF 1-3 [micro]M SIZED LATEX PARTICLES AND SUSPENDED STAPHYLOCOCCUS EPIDERMIDIS. Esther Kim, Aim Foster, and chris Hansen, Southern Adventist University, Collegedale, Tennessee. A so-called optical tweezer setup is being constructed to trap and manipulate Staphylococcus epidermidis. As a preliminary step, the capabilities of the optical trap were tested using small latex spheres (1-3 [micro]m) in place of bacteria. Results from these studies and initial attempts to trap planktonic bacteria will be presented.

THE EFFECTIVENESS OF A FAR LATERAL L5-S1 MICRODISCECTOMY IN PAIN REDUCTION. Jamie Griffin, Southern Adventist University, Collegedale, Tennessee. Diagnosis of far lateral disc herniations has become more common in recent years. This study describes the surgical procedure used for L5-S1 far lateral disc herniations, shows the benefits derived from a far lateral approach, and retrospectively evaluates the outcome of the surgery. Eight patients were included in the study, five females and three males. The mean age was 62 years (range 45-77 years). VAS pain scale, OSW index, and SF-36 forms were used to evaluate the surgical outcome. Both the VAS pain scale and OSW index were improved postoperatively.

MATURATION OF DENDRITIC CELLS MAY EXCEED ESTIMATED 24 HOUR PERIOD. Sarah Reeves, Southern Adventist University, Collegedale, Tennessee. Dendritic cells (DCs) are responsible for antigen uptake, presentation, and stimulation of T cells responsible for recognizing these antigens. During their immature stage they constantly endocytose fluids and particles from the interstitial fluid in the periphery, such as the skin, organs, and mucous membranes. Maturity is reached after the uptake of antigen stimulates the loading of a foreign peptide on their major histocompatibility complex class II (MHC II) molecules, which then are expressed on the cell surface. Dendritic cells cease antigen uptake and presentation at some point between the uptake of a maturation stimulus (such as bacteria) and the point at which the DC is fully mature. Dendritic cells have been estimated to have a 24 h maturation period. However, recent experimental results indicate this period is longer than 24 h.

RADIO SIGNALS FROM JUPITER. Yvan De Repentigny, Roane State Community College, Harriman, Tennessee. The project consists of assembling a short-wave receiver that picks up radio signals from the great planet Jupiter. This receiver contains many electronic components such as resistors, capacitors, inductors, and a transistor among other pieces of hardware. Fabrication included the handling of small, fragile, electronic parts, most of which are mounted and soldered onto a printed circuit (PC) board. A dipode antenna was installed outside. Once the radio became functional, it was connected to a computer. The monitoring system called Radio Jove Program was implemented so that data can be observed not only at Roane State, but also from anywhere else in the world, even your own living room.

ASTROPHOTOGRAPHY AT THE TAMKE-ALLAN OBSERVATORY. Whitney Styles and Lorry Byrge, Roane State Community College, Harriman, Tennessee. We have done Planetary and Cometary Astrophotography at the Tamke-Allan Observatory using two CCD Cameras and an 8" Schmidt-Cassegrain Telescope. The two cameras are the Starlight X-press MX5-C color CCD Camera and a Santa Barbara Instruments Group CCD Camera. These photographs were made over a period of six months. In several cases, selected photographs were overlaid to get significant improvements in contrast and resolution. This work was done to gain experience in taking astrophotographs of faint and distant objects. We expect to apply these techniques to obtain astrophotographs of planetary and diffuse nebulae and galaxies.
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Publication:Journal of the Tennessee Academy of Science
Geographic Code:1U6TN
Date:Jul 1, 2002
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