Physiology Commons^™

Functional Consequences Of Matrix Metalloproteinase-1 Over-Expression In Human Gliomas, Emily Mullet

Theses and Dissertations

Malignant brain tumors are among the deadliest of human cancers. Despit recent advancements in conventional therapies, glioblastomas remain incurable, largel y due to their ability to invade surrounding tissue. Matrix metalloproteinases are thought to contribute to the invaseive phenotype of human gliomas. Absent in normal brain, matrix metalloproteinase-1 (MMP-1) has been shown to be present in gliomas, and in particular in glioblastoma multiforme (GBM). To begin to examine the role of MMP-1 in these tumore, two human glioma cell lines were stably transfected with MMP-1 cDNA. Confirmation of MMP-1 over-expression in these cells was achieved through real-time PCR and Western …

Comparison Of Leukocyte Classes Most Likely To Cause Vascular Dysfunction In Preeclampsia, Kristen Anne Cadden

Theses and Dissertations

Leukocytes are activated in women with preeclampsia, but the class of leukocyte most likely to cause vascular dysfunction is not known. We hypothesized that neutrophils may be the class of leukocyte most involved in causing this dysfunction because neutrophils are the most abundant of the leukocytes and their numbers increase during pregnancy. In this study we compared vascular infiltration of neutrophils (CD66b) with monocytes/macrophages (CD14) and lymphocytes (CD99) in normal non-pregnant women (NNP), normal pregnant women (NP), and preeclamptic women (PE). There was no significant difference in the infiltration of lymphocytes into the maternal vasculature in PE as compared to …

Anatomical Bases For Auditory Projections To Suprasylvian Visual Areas In The Cat Cerebral Cortex, Giriaj K. Sharma

Theses and Dissertations

How the neural representations of different sensory modalities transition from one to another is an unexplored issue of cortical organization. The present experiments addressed this problem by examining auditory projections to the lateral suprasylvian visual area (LSS) of the cat using neuroanatomical tract tracing methods. Injections of tracer (Biotinylated Dextran Amine, BDA) were made into defined areas of the cat auditory cortex. Following transport and tissue processing, a light microscope with a digitizing stage was used to visualize and plot labeled auditory projections to the LSS. The results showed that all auditory cortices tested demonstrated projections to a restricted portion …

Energy Value In Llamas (Lama Glama) Fed With Alfalfa Hay (Modicago Sativa) And Barley (Hordeum Vulgare) For Apparent Digestibility In Vivo In The National Camelid Germplasm Bank (Ceac), Edwin Gonzalo Ugarte Huanca

Theses and Dissertations

In this experiment, we used four male llamas that were three to four years of age from the Khara race. They were divided into two ad libitum feeding groups. The digestible energy (ED) was determined using samples that were sent to the laboratory. These samples were derived from a conventional in vivo assay using the method of total fecal collection in order to determine the difference between energy consumed and energy excreted. Metabolizable energy was calculated by deducting digestible energy, energy loss in the urine and energy loss in the gases (methane). Urinary energy was determined through the measurement of …

Long-Term Cardioprotection With Phosphodiesterase-5 Inhibition Against Ischemia-Reperfusion Injury: Role Of Nitric Oxide., Vladimir Paul Daoud

Theses and Dissertations

Recent studies have shown that the potent phosphodiesterase-5 (PDE-5) inhibitor, sildenafil citrate, induces a powerful cardioprotective effect against ischemia-reperfusion (I/R) injury in rabbit and mouse hearts. However, the effect of this drug in inducing long-term protection against I/R injury remains unknown. The goal of this study was to identify the duration of the protective window of sildenafil citrate as well as vardenafil, a more potent PDE-5 inhibitor. Rabbits were treated with sildenafil (0.7 mg/kg, iv), vardenafil (0.143 mg/kg), or an equivalent volume of saline. After 24 hrs, 48 hrs, 96 hrs, or 7 days of sildenafil treatment, the hearts were …

The Effect Of Red Blood Cell Velocity On Oxygenation Measurements Using Resonance Raman Spectroscopy, Derrick Williams

Theses and Dissertations

Resonance Raman spectroscopy can be used to estimate the hemoglobin oxygen saturation. Previous studies have demonstrated that exposure of oxygenated red blood cells to laser illumination may result in photo-induced displacement of oxygen from hemoglobin. In this study, an in vitro model was used to evaluate the relationship between this photo-induced effect and the red blood cell velocity. A computer-controlled system was implemented to acquire variables such as red cell velocity, microvessel diameter and hemoglobin oxygen saturation at multiple sites in selected microvascular networks. Using this system, resonance Raman spectroscopy was employed to measure hemoglobin oxygen saturation gradients in arterioles …

Erythrocyte-Associated Transients In Capillary Po2 In The Rat Spinotrapezius Muscle During Hemodilution With Hespan And A Hemoglobin-Based Oxygen Carrier, Matthew Barker

Theses and Dissertations

Hemoglobin-based oxygen carriers for use as transfusion fluids have emerged as a leading technology directed at stemming shortages of a safe blood supply and providing a readily available resuscitation fluid in various trauma situations. The purpose of this investigation was to determine the effects of isovolemic hemodilution with Hespan and a hemoglobin-based oxygen carrier (HBOC) on erythrocyte-associated transients (EATs) in capillary PO2. The particulate nature of blood flow in capillaries, when observed from a stationary observation point, results in fluctuations of PO2 as alternating red blood cells and plasma gaps move through the detection region. Therefore, through experimental methods which …

Novel Strategies In Cardioprotection Against Ischemia/Reperfusion Injury, Fadi N. Salloum

Theses and Dissertations

Cell damage represents a major pathomechanism in many diseases of high clinical interest, such as myocardial infarction (MI), where it plays an important role in ischemia-reperfusion (I/R) injury. Considerable progress has been made towards identifying physiological and pharmacological agents that play a key role in myocardial preconditioning against I/R injury and also elucidating the molecular changes leading to such protection.Second messengers in cellular signaling pathways, such as cGMP have been well implicated as key players in ischemic and pharmacological preconditioning (PC) of the heart. Phosphodiesterase type 5 (PDE-5) is an enzyme that specifically hydrolyzes cGMP thereby decreasing its tissue concentration. …

Acute And Chronic Effects Of Artificial Rearing On Rat Genioglossus Muscle, Wayne Allen Moore Jr.

Theses and Dissertations

In most mammals, nutritive suckling is critical during the early neonatal period. The genioglossus (GG) muscle in rat plays an important role in protruding the tongue for efficient suckling. The purpose of this study was to examine the contractile properties and myosin heavy chain (MHC) phenotype of the GG following an early period of artificial rearing, which reduced nutritive suckling. Beginning at three days of age Sprague-Dawley rats were fed via implanted gastric cannula until postnatal day 14 (P14). At P14, artificially reared (AR) rat pups were either placed with a lactating dam until the end of the weaning period …

Type-5 Phosphodiesterase Inhibition In The Prevention Of Doxorubicin Cardiomyopathy, Patrick William Fisher

Theses and Dissertations

Prior studies have demonstrated the effect of diazoxide in protecting against apoptosis via mitochondrial KATP channel opening in vitro. The current investigations are designed to determine if sildenafil, a phosphodiesterase-5 inhibitor and known mitochondrial KATP channel opener, would protect against chronic doxorubicin cardiomyopathy both in vivo and in vitro.Male ICR mice were randomized to 1 of 4 treatments: saline, sildenafil (0.7 mg/kg IP), doxorubicin (5 mg/kg IP), and sildenafil (0.7 mg/kg IP)+doxorubicin. Apoptosis was determined using the terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling and in situ oligo ligation methods. Desmin distribution was determined via immunofluorescence. Bcl-2 was analyzed by …

Phosphorylation Of Skeletal Muscle Acetyl-Coa Carboxylase By Ampk Enhances Palmitoyl-Coa Inhibition, Dustin S. Rubink

Theses and Dissertations

Acetyl-CoA carboxylase (ACC) catalyzes the formation of malnoyl-CoA, which in turn controls the rate of fatty acid metabolism. ACC beta or 2 has been shown to be localized on the mitochondria in close proximity to carnintine palmitoyl transferase 1 (CPT-1), the enzyme responsible for the influx of acyl-CoA into the matrix where beta oxidation takes place. CPT-1 is inhibited by malonyl-CoA produced by ACC. It has been well documented that AMP activated kinase (AMPK) when activated phosphorylates and inactivates ACC. ACC is controlled allosterically by citrate, which activates, and by palmitoyl-COA, which inhibits. In this study, we asked the question, …

Mechanism Governing The Cellular Susceptibility To Secretory Phospholipase A2, Lauren Blackburn Jensen

Theses and Dissertations

Secretory phospholipase A2 (sPLA2) is an important part of apoptosis and disposal of damaged and dying cells. However, healthy cells are not susceptible to attack by sPLA2. Recent studies have focused on membrane properties necessary to induce susceptibility in both artificial and biological membranes. Hydrolysis of phospholipids by sPLA2 requires at least two preliminary steps: first, adsorption of the enzyme to the cellular membrane, and second, movement of a phospholipid into the active site of the enzyme. We determined the effects of susceptibility on each of the two steps and determined the contributions changing the equilibrium constants have on susceptibility. …

Effects Of Emphysema And Chronic Hypoxemia On Skeletal Muscle Oxygen Supply And Demand, John D. Lowman Jr.

Theses and Dissertations

Skeletal muscle dysfunction in chronic obstructive pulmonary disease (COPD) is a condition in which peripheral skeletal muscle undergoes myopathic changes which impair muscle function, limit physical performance, and can lead to significant disability. While the etiology of the dysfunction is unknown, this study was conducted to test the hypothesis that chronic hypoxemia leads to alterations in oxygen transport and muscle function. A primary objective was to validate elastase-induced emphysema in rats as an animal model of skeletal muscle dysfunction in COPD.Arterial blood gases were used to determine the severity of hypoxemia and sodium dodecyl sulfate- polyacrylamide gel electrophoresis was used …

Implementation And Validation Of A Real-Time Wireless Non-Invasive Physiological Monitoring In A High-G Environment, H. Aydin Akcivi

Theses and Dissertations

The overall purpose of this research is to develop a system capable of real-time personal positioning and physiological monitoring. The system will be composed of a shirt having non-invasive physiological sensors, Global Positioning System (GPS) receiver, wireless data transceiver, and real-time PC-based control station. The specific purpose of this research phase was to determine the performance capabilities of a modified LifeShirt™ alone (without GPS) in a high gravitational force environment with the data being sent wirelessly in real-time. The LifeShirt™ was modified with a real time wireless transmission system.

Vascular Cell Dysfunction And Transendothelial Migration Of Neutrophils In Preeclampsia, Courtney Elizabeth Leik

Theses and Dissertations

Oxidative stress, hyperlipidemia, neutrophil activation and endothelial cell dysfunction are characteristic of women with preeclampsia. We used in vitro experiments to test if a combination of oxidative stress and linoleic acid favors a mechanism for neutrophil transendothelial migration. We used linoleic acid because it is one of the fatty acids elevated in preeclampsia and the precursor for arachidonic acid and its inflammatory metabolites. For these studies, we developed a methodology for isolating and Culturing human vascular smooth muscle cells from placental chorionic plate arteries. Treatment of these cells with an oxidizing solution enriched with linoleic acid, but neither component alone, …

Pilot Mental Workload Calibration, Jeremy B. Noel

Theses and Dissertations

Predicting high pilot mental workload is important to the U.S. Air Force because lives and aircraft can be lost when errors are made during periods of mental overload and task saturation. Current research efforts use psychophysiological measures such as electroencephalography, cardiac, ocular, and respiration measures in an attempt to identify and predict mental workload levels. The primary focus of this effort is the development of a calibration scheme that allows a small subset of salient psychophysiological features developed using actual flight data for one pilot on a given day to accurately classify pilot mental workload for a separate pilot on …

Functional Characterization Of Mitogen-Dependent And Self-Perpetuating Nb2 Lymphoma Cell Lines, Charlotte Cockrell

Theses and Dissertations

This investigation involved the functional characterization of four Nb2 sub lines (Nb2-U- 17, Nb2-l l , SFJCD l , and D5) for their mitogenic and apoptotic responses to DEX ± PRL treatment. Many protein factors have been implicated to be crucial in controlling the apoptotic and mitogenic pathways. In conjunction with functional studies, an immunocytochemical investigation of four protein signals (NFKB, IKBa, STAT 5b, and the GR) was undertaken in an attempt to establish a relationship between the functional responsiveness of a given cell line and the concentration of a particular protein marker. Comparison of the functional data obtained for …

Correlation Of Visualized Glucocorticoid Receptor And Apoptosis In Individual Clones Of Nb2 Cells, Devang M. Patel

Theses and Dissertations

The Nb2 lymphoma cell line is susceptible to glucocorticoid (GC)-induced apoptosis in the absence of mitogen and this effect is inhibited by the mitogen prolactin (PRL). This process is believed to be mediated by the glucocorticoid receptor (GR) and various downstream signals. The purpose of this study was to use the limiting dilution method to isolate subsets of Nb2 clones which expressed either highly enriched amounts of GR or an absence of GR and to relate the amount of GR to the magnitude of GC induced cytolysis. The presence of GR in these clones was determined by immunocytochemistry (ICC) using …

Examination Of Signals Involved In Dexamethasone Induced Apoptosis In Nb2 Lymphoma Cells, Suhas Badarinath

Theses and Dissertations

Consistent with previous studies, we demonstrated that dexamethasone (Dex) caused cytolysis/apoptosis in log phase Nb2 lymphoma cells, while prolactin (Prl) inhibited this effect. The Nb2 model was used to investigate the mechanisms of apoptosis control with the aid of immunocytochemistry (ICC). We established with absorption the specificity of staining due to Fas, Fas Ligand, Bcl-2, and Bax antibodies (the specificity of anti-p53 could not be verified). Dex-induced cytolysis/apoptosis was detected in synchronized (G⁰/G¹) cells after 6 and 8 hours of Dex exposure. A novel, computerized technique was used to quantitate the proportion of cells immunostained for the signals of interest …

Immunocytochemical Study Of Apoptosis Signaling In Nb2 Lymphoma Cells, Angelo P. Guanzon

Theses and Dissertations

In the absence of mitogen, administration of Dexamethasone (Dex) induces apoptosis, or programmed-cell death in the Nb2 lymphoma cell. Addition of prolactin (Prl), on the other hand, blocks this effect. As a model for apoptosis, we were able to investigate this Dex-Prl interaction by means of a morphological approach: one that could be visualized under a light microscope. This approach allowed us to achieve several aims. First, we were able to develop a method of cell quantification befitting a morphological study based upon the hemacytometer. Second, with Trypan Blue exclusion, we were able to verify Dex/Prl-responsiveness in the Nb2 cells. …

Electrophysiological Effects Of Lysoplasmenylcholine On Rabbit Ventricular Myocytes, Ray Caldwell

Theses and Dissertations

Myocardial ischemia activates a phospholipase A2 that targets plasmalogen phospholipids and liberates 1-0-alkenyl-Iysoplasmenylcholine (LPLC) in preference to 1-0- acyl-Iysophosphatidylcholine (LPC). Although LPC is a pro arrhythmic ischemic metabolite, the effect of LPLC on cardiac electrophysiology is unknown. At the lowest doses investigated, LPLC induced spontaneous contractions in otherwise quiescent rabbit ventricular myocytes significantly faster than LPC. Spontaneous contractions developed with median times of 16.4 (n = 64), 27.4 (n = 36), and >60 min (n = 25) during exposure to 5, 2.5, and 1 JlM LPLC compared with 38.0 (n = 48) and >60 min (n = 29) for 5 …

The Effects Of Carboxyl-Group Specific Modification And Triiodo-L-Thyronine On Cardiac Sodium Channels, Samuel C. Dudley

Theses and Dissertations

The patch clamp method was used to evaluate the effects of 3,5,3'-triiodo-L-thyronine (T₃) and carboxyl modification on adult rabbit ventricular Na⁺ channels. In contrast to TTX-sensitive Na⁺ channels, Ca²⁺ block of cardiac Na⁺ channels was not prevented by selective carboxyl modification by trimethyloxonium (TMO) or water soluble carbodiimide (WSC). In 2 mM Ca²⁺, TMO-treated patches exhibited 3 discrete conductance (γ_Na) levels. An abbreviation of mean open time (MOT) accompanied each decrease in γ_Na. The effects on channel gating of elevating external Ca²⁺ differed from those of TMO …

Role Of Newly Synthesized Steroid Hormone Antagonists In Adrenocortico-Steroid Hormone-Induced Hypertension, Justicia Opoku-Edusei

Theses and Dissertations

Excess adrenocorticosteroid hormones such as glucocorticoids and mineralocorticoids is well known to induce hypertension in several animal species as well as in humans. Therefore, the development of potent and specific glucocorticoid and mineralocorticoid antagonists with antihypertensive effects is clinically necessary. steroid hormone antagonists being used therapeutically present serious endocrinology side effects such as the widely used antimineralocorticoid, spironolactone. The antiglucocorticoids available so far have been active only in vitro or only weakly in viva. Recently, three new exciting adrenocorticosteroid hormone antagonists have been synthesized. RU 486 is a potent antiglucocorticoid (and antiprogesterone with potential as an abortifacient), RU 26752 and …

Effects Of Hematocrit Variations On Microcirculatory Hemodynamics And Oxygen Transport In Hamster Striated Muscle, Lih Kuo

Theses and Dissertations

Experiments were performed to investigate the influence of isovolemic hemodilution and hemoconcentration on microcirculatory hemodynamics and oxygen transport in the hamster cheek pouch retractor muscle. Measurements of red blood cell velocity, microvessel hematocrit, vessel diameter, segment length (L), hemoglobin oxygen saturation (SO₂) and longitudinal SO₂ gradient (ΔSO₂/L) were made in four arteriolar branching orders before and after isovolemic exchange with plasma (hemodilution) or packed red blood cells (hemoconcentration).

In the study of hemodilution, systemic hematocrit was reduced from 52 to 33% in 23 hamsters. This degree of hemodilution resulted in an average decrease in microcirculatory …

Tissue Chromium Levels :|Bautopsy Study In Diabetic And Non-Diabetic American (Pima) Indians, Leslie O. Hansen

Theses and Dissertations

Tissues (liver, spleen, pancreas, and aorta) and hair taken at autopsy from diabetic and non-diabetic southwestern Indians (mainly Pima) were analyzed for chromium (Cr) using flameless atomic absorption spectrophotometry. The Cr levels in both tissues and hair from diabetic subjects were consistently lower than in those from non-diabetic individuals. There were so few individuals in each group that it was not possible to accurately correlate a given tissue either with any other tissues or hair.

Activation Of The Gamma Motor System In The Cat Following Selective Stimulation Of The Motor Cortex And The Pyramidal Tract, James Elliott Forbes

Theses and Dissertations

Until the mid to late 1800's, the cerebral hemispheres were considered to be only the sites of mentation and intellectual activity. On the basis of his observations of epileptic patients, HughIings Jackson (cited from Walshe, l935a) theorized that the cerebral hemispheres were also sites of motor control and sensory experience. The electrical excitability of the cerebrum was first demonstrated by Fritsch and Hitzig in 1870. Since then the motor representation of the various muscles has been mapped out and the types of movement in response to stimulation of the motor cortex and the pyramidal tract have been thoroughly studied.

Mammalian …

Modulation Of Cortical And Pyramidal Tract Induced Motor Responses By Electrical Stimulation Of The Basal Ganglia, Roberta Ann Newton

Theses and Dissertations

Since the early 1800's, the basal ganglia have been recognized as an extrapyramidal subcortical motor area. Much of the knowledge of basal ganglia involvement in movement has been obtained through clinical symptomology. Consideration of the basal ganglia as a pure inhibitory influence upon motor regulation was a concept generated by early researchers (24,57,58). In spite of the fact that the basal ganglia was considered an inhibitory center, it was known that the basal ganglia produced fore limb flexion or contraversive head ‘turning. At the present, both facilitatory and inhibitory influences upon motor activity have been demonstrated (50). Physiological mechanisms underlying …

Glycogen Levels In Cardiac And Skeletal Muscle Of Rats Recovering From Exercise, Walter Talley Judd

Theses and Dissertations

In seeking answers to questions about how the human body functions under stressful situations, scientists, coaches, doctors, and athletes in general have all wondered about the role of exercise in the maintenance of good health. Good cardiovascular health, especially, is sought ardently, as it appears to be a major key to overall body fitness. Good cardiovascular health appears to go hand-in-hand with proper diet, proper rest, and proper exercise (1, 2).

The exercise phenomenon has attracted much attention and poses many questions. Just what is occurring when a person or an animal gets "in shape" by exercising. What bodily changes …

The Effects Of Alcohol On Three Levels Of Complex Human Behavior, Grady Vancil Maraman

Theses and Dissertations

That alcohol affects human behavior has been known for centuries. However, how and why it affects behavior has not been precisely established despite extensive research and study. The inconsistent action of alcohol at different doses on different tissue systems and on different response systems has been well documented (Kalant 1 referenced in 39). The exact sites of action of alcohol in the central nervous system and the relative influence of each of these sites in cognitive and motor behavior are not known. The primary purpose of this experiment was to study the effects of blood alcohol concentrations below 0.100 percent …