Organisms Commons^™

The Guinea Pig Ileum Lacks The Direct, High-Potency, M2-Muscarinic, Contractile Mechanism Characteristic Of The Mouse Ileum, Michael T. Griffin, Minoru Matsui, Rennolds S. Ostrom, Frederick J. Ehlert

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We explored whether the M2 muscarinic receptor in the guinea pig ileum elicits a highly potent, direct-contractile response, like that from the M3 muscarinic receptor knockout mouse. First, we characterized the irreversible receptor-blocking activity of 4-DAMP mustard in ileum from muscarinic receptor knockout mice to verify its M3 selectivity. Then, we used 4-DAMP mustard to inactivate M3 responses in the guinea pig ileum to attempt to reveal direct, M2 receptor-mediated contractions. The muscarinic agonist, oxotremorine-M, elicited potent contractions in ileum from wild-type, M2 receptor knockout, and M3 receptor knockout mice characterized by negative log EC50 (pEC 50 ) values ± …

Resistance Training And Bone Mineral Density During Growth, M. Z. Smith, B. M. Goettsch, R. D. Van Ramshorst, J. A. O'Brien, S. V. Jaque, Ken D. Sumida

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

This study examined the efficacy of two different resistance training programs in enhancing bone modeling and bone mineral density (BMD) in maturating rats. One exercise mode involved lifting a lighter weight with more repetitions (LI), while the other regimen involved lifting a heavier weight with fewer repetitions (HI) where the total volume of work between exercise programs was equivalent by design. Twenty-three male rats were randomly divided into control (Con, n = 8), LI (n = 7), and HI (n = 8) groups. The LI and HI groups were conditioned to climb a vertical ladder with weights appended to their …

Interrupted Vs. Uninterrupted Training On Bmd During Growth, B. M. Goettsch, M. Z. Smith, J. A. O'Brien, G. V. Gomez, S. V. Jaque, Ken D. Sumida

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

This study compared a resistance training program where the exercise was uninterrupted (UT, i.e., continuous repetitions) against a resistance training program where the exercise was interrupted (IT, i.e., 3 exercise sessions during a training day) for enhancing bone modeling and bone mineral density (BMD) in maturating animals. The total volume of work performed between the two resistance training programs was equivalent by design. 24 young male rats were randomly divided into Control (Con, n = 8), UT (n = 8) and IT (n=8) resistance trained groups. The UT and IT groups were conditioned to climb a vertical ladder with weights …

Molecular Screening Of Azoreductase Gene And Its Activity In Human Intestinal Bacteria, Syndia S. Todd

McCabe Thesis Collection

The intestinal microflora are capable of performing a wide variety of metabolic transformations. "The intestinal bacteria can enhance the function of the entire gastrointestinal tract, protect against pathogenic, maintain the vital chemical balance of the gastrointestinal system, and produce needed vitamins and hormones" (http;//www.upwardquest.com/crit2.html). Some of the products of this metabolism have been associated with carcinogenic processes, such as cancer, tumor formation, gastrointestinal disease, and infections. The ability of human intestinal microbes to interact with metabolites directly or after recirculation may contribute toward different toxicological disorders and disease.

The purpose of this study is to characterize and isolate the azoreductase …

Rapid Determination Of Reduced And Oxidized Glutathione Levels Using A New Thiol-Masking Reagent And The Enzymatic Recycling Method: Application To The Rat Liver And Bile Samples, Imam H. Shaik, Reza Mehvar

Pharmacy Faculty Articles and Research

A microtiter plate assay for quantitation of reduced (GSH) and oxidized (GSSG) glutathione in the rat liver tissue and bile is described. The assay is based on the established enzymatic recycling method and a new thiol-masking reagent, 1-methyl-4-vinyl-pyridinium trifluoromethane sulfonate (M4VP). Samples were first processed by homogenization with (liver) or addition of (bile) sulfosalicylic acid. The total glutathione and GSSG were then determined before and after rapid (>= 2 min) and efficient (100%) masking of the GSH content of the samples with M4VP followed by the enzymatic recycling assay. The percentages of error and coefficient of variation of the …

Inhibition Modifies The Effects Of Slow Calcium-Activated Potassium Channels On Epileptiform Activity In A Neuronal Network Model, Keun-Hang Susan Yang, Piotr J. Franaszczuk, Gregory K. Bergey

Mathematics, Physics, and Computer Science Faculty Articles and Research

Generation of epileptiform activity typically results from a change in the balance between network excitation and inhibition. Experimental evidence indicates that alterations of either synaptic activity or intrinsic membrane properties can produce increased network excitation. The slow Ca2+-activated K+ currents (sI AHP) are important modulators of neuronal firing rate and excitability and have important established and potential roles in epileptogenesis. While the effects of changes in sI AHP on individual neuronal excitability are readily studied and well established, the effects of such changes on network behavior are less well known. The experiments here utilize a defined small network model of …

Levels Of Intravenous Enterococcus Faecalis That Cause Heart Colonization, Louis Zane Stromberg

Loma Linda University Electronic Theses, Dissertations & Projects

While previous studies have shown that presence of bacteria in systemic circulation can cause infective endocarditis, there is no information on the specific amount of bacteria necessary to cause this condition. The purpose of this study was to establish the minimum level of circulating bacteria that will cause colonization of damaged heart valves in rats. Fifty-two Sprague-Dawley rats were anesthetized and their heart valves were damaged using an established protocol. A clinical isolate of Enterococcus faecalis was transformed with a plasmid bearing the luxF and Chloramphenicol cassettes to label the bacteria with the light-emitting protein. After four weeks, the rats …

Hepatic Disposition Of Cyclosporine A In Isolated Perfused Rat Livers, Reza Mehvar, Anjaneya Chimalakonda

Pharmacy Faculty Articles and Research

PURPOSE. To develop an isolated perfused rat liver model to study the hepatic disposition of cyclosporine A (CyA) in both sexes.

METHODS. Livers were isolated from male (n = 6) and female (n = 7) rats and perfused with a physiological buffer in a single-pass manner. A bolus 1-mg dose of CyA was injected into the inlet catheter and periodical samples (0-15 min) were collected from the outlet perfusate. The concentrations of CyA in the outlet perfusate, collected bile (0-15 min), and liver tissue (at the end of perfusion) were quantitated by HPLC and subjected to statistical moment analysis. …

Dextran-Methylprednisolone Succinate As A Prodrug Of Methylprednisolone: Plasma And Tissue Disposition, Xiaoping Zhang, Reza Mehvar

Pharmacy Faculty Articles and Research

Plasma and tissue disposition of a macromolecular prodrug of methylprednisolone (MP), dextran (70 kDa)–methylprednisolone succinate (DMP), was studied in rats. Single 5‐mg/kg doses of DMP or unconjugated MP were administered into the tail veins of different groups of rats (n  = 4/group/time point). Blood (cardiac puncture) and tissues (liver, spleen, kidney, heart, lung, thymus, and brain) were collected at various times after DMP (0–96 h) or MP (0–2 h) injections. Concentrations of DMP and MP in samples were analyzed by size‐exclusion chromatography (SEC) and reversed‐phase high‐performance liquid chromatography (HPLC), respectively. Conjugation of MP with 70‐kDa dextran resulted in 22‐, …

Problem Of Common Fungus Infections, Calvin J. Dillaha

Journal of the Arkansas Academy of Science

No abstract provided.

Kidney Of The Frog, Felix Taubman

Bachelors’ Theses

The frog has been used exclusively in both high school and college as the main source of experimental biological and zoological studies. Because it is so easily obtained and so finely adapted to our purposes, we chose it as the specimen upon which to do our thesis work. Much has been done experimentally on the kidneys with the frog. The purpose of this thesis is to present a general view of the external and microscopic anatomy of the frog kidney and with this as a groundwork to present the problems of secretion; whether secretion is carried on by the renal …