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The Phosphoinositide Second Messenger System And The Regulation Of The Release Of Growth Hormone From Purified Rat Somatotrophs, Michelle Brigid French

Digitized Theses

The release of growth hormone (GH) from the somatotrophs of the anterior pituitary is controlled by two hypothalamic hormones growth hormone-releasing factor (GRF) and somatostatin (SRIF). The former stimulates, while the later inhibits the release of GH. cAMP and Ca{dollar}\sp{lcub}2+{rcub}{dollar} are second messengers for GRF. Previous reports suggested that the phosphoinositide second messenger system was an additional pathway for GRF. Our purpose was to examine the role of this system in GRF action. We used perifused dispersed anterior pituitary cells and purified somatotrophs from male rats to ask: (1) Does activation of protein kinase C stimulate the release of GH …

Mucus-Secreting Cells Of The Colon In Health And Disease, Deena Patricia Rodney

Digitized Theses

Two morphologically distinct mucous cell types have been described in the ascending colon of rat and man. These include the goblet cells and non-goblet mucous (NGM) cells. The latter are known in the rat as "deep crypt secretory" (DCS) cells.;The purpose of this study was to examine various aspects of these NGM cells, including the histochemical nature of the rat DCS cell and human NGM cells. In addition, the reactions of the NGM cells were studied and compared to those of the goblet cells in an experimental model of colitis and in human IBD. A range of mammalian species, classed …

31-Phosphorous, Nuclear Magnetic Resonance Spectroscopy Studies Of Exercising Human Muscle, Gregory D. Marsh

Digitized Theses

Phosphorous 31, nuclear magnetic resonance spectroscopy {dollar}(\sp{lcub}31{rcub}{dollar}P NMRS) was used as a non-invasive probe of forearm muscle metabolism in three studies of healthy men and women. Specific objectives of the studies were to: (1) observe the changes in high energy phosphates and intracellular pH in muscle, during a ramp exercise protocol, (2) study the effect of endurance training on muscle metabolism and evaluate the utility of the forearm ramp test as a means to assess muscle oxidative capacity, and (3) describe the kinetics of phosphocreatine (PCr) and inorganic phosphate (Pi) metabolism during the on and off transient response to moderate …

Regulation Of Porcine Thecal Cell Steroidogenesis By Locally Produced Factors, Heidi E. Engelhardt

Digitized Theses

Regulation of steroidogenesis (measured by radioimmunoassay) by peptides produced within the ovary was investigated in monolayer cultures of porcine thecal cells (TC). In serum-free cultures LH but not FSH stimulated accumulation of androstenedione (Ad) and progesterone (P). No further accumulation of either steroid occurred after 19h. Addition of fetal bovine serum (FBS; optimal at 1%) maintained steroidogenesis for 3-4 days, but Ad production declined, and, in the presence of LH, P production increased. IGF-I plus LH markedly enhanced P production, an effect most pronounced after 3-4 days of treatment, and not associated with increases in DNA per well. Changes in …

Myosin Transformation In Thyrotoxic Rat Soleus Muscle, Margaret Mary Sopper

Digitized Theses

Male Sprague-Dawley rats were injected with 300{dollar}\mu{dollar}g/kg body weight of Triiodo-L-thyronine (T{dollar}\sb3{dollar}) and L-thyroxine (T{dollar}\sb4{dollar}) on alternate days over a 28-day treatment period. Thyrotoxicosis was confirmed by increased serum T{dollar}\sb3{dollar} levels and a pronounced ventricular hypertrophy (p {dollar}\le{dollar} 0.05 after 5 days). The effects of thyroid hormone on isometric contractile properties of the slow-twitch soleus muscle were studied in situ after 2, 5, 7, 15, 21 or 28 days. Time to peak tension (TPT) and one half relaxation time (1/2 RT) were significantly reduced after 5 days (T-5, p {dollar}\le{dollar} 0.05) and reached 56.7% and 51.1% of age-matched control values …

The Effects Of Gastrin Releasing Peptide In Fetal Sheep, Pregnant Sheep And Non Pregnant Sheep, Pamela Elizabeth Houghton

Digitized Theses

These studies examined the hypothesis that GRP stimulates insulin release from the endocrine pancreas of ovine fetuses. This could occur due to the action of GRP directly within the fetal compartment or due to indirect effects of GRP on glucose and insulin concentrations in the maternal compartment which in turn influences the availability of glucose for transplacental transfer to the fetus and hence produce alterations in fetal insulin release.;The studies performed provided the following results: (1) IR-GRP was detectable in nerves of the GI tract and in the systemic circulation but not in the pancreas of fetal and adult sheep; …

Expression Of The Murine Ornithine Decarboxylase Gene In Transgenic Nicotiana Tabacum Var Xanthi, Richard Anthony Descenzo

Doctoral Dissertations

Ornithine decarboxylase (ODC), arginine decarboxylase (ADC), and S-adenosyl-methionine decarboxylase (SAMDC) are the three key regulatory enzymes for polyamine (putrescine, spermidine, and spermine) biosynthesis. In order to gain more insight into the relationship between polyamine metabolism and other physiological processes, research was undertaken to obtain increased putrescine biosynthesis in tobacco by overexpression of a murine ODC cDNA.

Both a full-length and a truncated murine ODC cDNA were cloned into a binary expression vector containing the Cauliflower Mosaic Virus (CaMV) 35S promoter. Using standard leaf-disc transformation procedures, transgenic tobacco plants containing either the full length or the truncated ODC cDNA were obtained. …

The Effect Of Co-Culture Systems From Non-Reproductive Origins On The Development Of Superovulated And In Vitro Fertilized Bovine Embryos., Hak-Nam Kim

LSU Historical Dissertations and Theses

The objective of this experiment was to compare in vitro development of bovine embryos obtained from superovulation and in vitro fertilization (IVF) in two unique monolayer co-culture systems, bovine fetal spleen cell monolayers (BFS) and chick embryo fibroblast monolayers (CEF). To test the possible harmful effects of these co-culture systems, 225 murine morula-stage embryos were cultured for 72 hours with these monolayers. The percentage of hatched embryos was 62.7% in culture medium alone, 76% in BFS and 57.3% in CEF. BFS and CEF did not induce any detectable harmful effect on these developing murine embryos. When 60 transferable morula-stage bovine …

Metabolic Pathways Associated With Glycogen Storage In Chronically Active And Normal Skeletal Muscle., Robert James Talmadge

LSU Historical Dissertations and Theses

To determine the pathways used for glycogen synthesis in chronically active and normal muscle, muscles from C57B1/6J dy$\sp{\rm 2J}/$dy$\sp{\rm 2J}$(dy$\sp{\rm 2J}$) mice were evaluated biochemically and histochemically. The gastrocnemius muscle (GAST) of the dy$\sp{\rm 2J}$ mouse, a chronically active muscle, contained twice as much glycogen and lactate as control GAST. The dy$\sp{\rm 2J}$ triceps muscle (TRI), which is not chronically active, showed no elevation in glycogen content. An intraperitoneal injection of $\sp{14}$C-lactate resulted in increased incorporation of $\sp{14}$C into glycogen by dy$\sp{\rm 2J}$ compared to control GAST. Both normal and dy$\sp{\rm 2J}$ GAST incorporated $\sp{14}$C into glycogen in an in …

Factors Responsible For The Differential Growth Of Brucella Abortus In Bovine Trophoblasts., Luis Ernesto Samartino

LSU Historical Dissertations and Theses

The interactions of bovine chorionic membrane explants (CAMs) as well as three different bovine trophoblastic cell lines with Brucella abortus were evaluated. The ability of B. abortus to infect and grow within the cells of these CAMs and within these cell lines was measured. In addition, prostanoid and hormone production by the trophoblastic cells after infection with B. abortus was measured. Internalization of B. abortus within the cells of CAMs derived from placentas from both 3-month-gravid cows and 7-month-gravid cows was similar. By 24 hours post-inoculation B. abortus replication in 7-months-derived CAMs was significantly greater than the replication occurring in …

Effects Of Chronic Administration Of Phenylbutazone On Reproduction In The Mare., Mareth Ellsworth

LSU Historical Dissertations and Theses

Phenylbutazone is a non-steroidal anti-inflammatory drug that acts by inhibiting prostaglandin synthesis. Prostaglandins are associated with crucial aspects of reproduction. In 5 experiments, mares were used to test the effects of phenylbutazone on reproduction. In all experiments, treatment was 2 g phenylbutazone or 10 ml physiological saline intravenously(control). In Experiment I, 9 mares were phenylbutazone-treated for 180 consecutive days and teased. Ovaries were palpated and cyclicity was verified by circulating progesterone concentrations. Thirty-six cycles were evaluated. Mares were then divided into treatment and control groups. Estrous mares were artificially inseminated. Non-surgical embryo collection was performed 7 to 8 days post-ovulation. …

Isolation And Characterization Of Macrophage Inhibitory Compounds From Mycobacterium Paratuberculosis., Murray Elison Hines Ii

LSU Historical Dissertations and Theses

Fractions exhibiting activity detrimental to the killing function of activated bovine monocyte/macrophages towards Candida albicans were obtained from Mycobacterium paratuberculosis. Active fractions were initially derived by ultrasonication of bacterial samples followed by ammonium sulfate precipitation, ion-exchange chromatography, gel filtration chromatography, heat precipitation, acid precipitation and alkali treatment. Two different fractions that exhibited marked inhibition of macrophage killing ability were derived and partially characterized. Novel methodology was developed to accomplish the task of lysis and fractionation of mycobacteria utilizing the Matrix Solid Phase Dispersion (MSPD) technique that appeared to be much more efficient and is certainly less time consuming and less …

Nuclear Transplantation: Intracellular Release And Extracellular Influx Of Calcium In Response To Electrofusion Pulse And Its Effect On Murine Oocyte Activation And Embryonic Development., Lee F. Rickords

LSU Historical Dissertations and Theses

The transplantation of early embryonic cell nuclei into oocytes in which the maternal chromosomes have been removed is a method by which multiple offspring of the same genotype can be produced. One critical factor required for successful development of nuclear transfer derived embryos is inducing the release of the recipient ooplasm from meiotic arrest (activation). This is accomplished during fusion of the two cells. The DC electrofusion pulse used to fuse the two cells together also activates the recipient ooplasm to resume meiotic events, however, the efficiency of electrofusion pulse induced activation remains low. It is known that activation of …

The Differential Effects Of Either X-Irradiation Or Thermal Stress On The Two Major Cell Types Of The Blastocyst Stage Murine Embryo., Joe Steve Capehart

LSU Historical Dissertations and Theses

The first objective of this investigation was to determine if either X-irradiation or thermal stress exerted differential effects on the two major cell types of the blastocyst stage murine embryo. Results of this study indicate that X-irradiation dosages of 0 rads, 500 rads, 600 rads, 700 rads, 800 rads, 900 rads or 1000 rads had no effect on the ability of treated embryos to either hatch or develop into trophoblastic outgrowths (P $<$.05). In contrast, X-irradiation treatment over the levels tested did have a detrimental effect on the ability of embryos to develop into trophblastic outgrowths possessing an ICM region (P $>$.05). X-irradiation over the levels tested had no effect on the mean two-dimensional outgrowth surface areas ($\mu$m$\sp2$) (P $>$.05). However, X-irradiation was found to have a …

Functional Morphology Of Gustatory Centers In The Brain Of The Channel Catfish, Ictalurus Punctatus., Charles Franklin Lamb Iv

LSU Historical Dissertations and Theses

Gustatory nuclei in the isthmic region of the metencephalon and in the posterior diencephalon of the channel catfish, Ictalurus punctatus, were examined anatomically and electrophysiologically. Neurons in the superior secondary gustatory nucleus (nGS) responded to taste and tactile stimulation of large peripheral receptive fields (RFs) that often included the epithelia of the oropharyngeal cavity and whole extraoral body surface. Taste responses to amino acids and nucleotides were dose-dependent, with detected thresholds from micromolar to millimolar concentrations. The RF organization within the nGS did not display the somatotopy present in the medullary gustatory nuclei. Anatomical labeling of secondary gustatory fibers showed …

Timed Daily Thermopulses Alter The Circadian Hormonal Regulation Of Glucose And Lipid Metabolism., Christopher Joseph De Souza

LSU Historical Dissertations and Theses

Studies were made in Syrian hamsters and Holtzman rats to examine roles for circadian rhythms in the control of body fats stores. Baseline and circadian rhythms of plasma insulin varied seasonally in the Syrian hamster. Baseline concentrations of the hormone were almost 4 times greater in scotosensitive female hamsters held on short daily photoperiods when they were fat than in lean animals at other seasons and other photoperiodic schedules. Additionally, plasma insulin levels in fat hamsters, but not in lean animals, peaked at light onset when lipogenic responsiveness to insulin is greatest. The circadian rhythms of plasma insulin are not …

Pcr Amplification Of Chlamydial Momp Genes: Detection, Sequence Analysis And Evolution., Bernhard Kaltenboeck

LSU Historical Dissertations and Theses

Sensitive detection and differentiation of the bacterial genus Chlamydia (C.) was accomplished using the polymerase chain reaction (PCR), and phylogenetic relationships among chlamydiae were inferred from DNA sequences of amplified major outer membrane protein (MOMP) genes. DNA of strains of C. psittaci was efficiently amplified using primers homologous to nontranslated regions of the MOMP genes (ompA). Portions of these reactions were reamplified using one different primer specific for an internal ompA sequence. Primary amplification products were differentiated by restriction analysis. Degenerate, inosine containing oligonucleotide primers homologous to terminal translated regions amplified DNA fragments of all chlamydial MOMP genes. Partial ompA …

Conceptus-Derived Immunosuppressive Factors And Their Role In Fetal Allograft Protection., Terri Lynn Roth

LSU Historical Dissertations and Theses

The role of conceptus-derived immunosuppressive factors in protecting the fetal allograft was investigated by first examining the immunosuppressive activity derived from ovine, caprine and hybrid conceptus trophoblast tissue. Medium conditioned by 20 day-old conceptus trophoblast tissue from each species suppressed sheep and goat lymphocyte proliferation (P $$.05) between the immunosuppressive effects of the three media on either sheep or goat lymphocytes. In subsequent studies, horse conceptus-conditioned medium (HCCM) derived from embryos at days 9, 15 and 26 of gestation, suppressed mitogen-stimulated horse lymphocytes (P $<$.001). HCCM maintained its suppressive activity following heating and repeated freeze-thawing. Using microconcentrator centrifugation, it was determined that the suppressor factor(s) was $>$100,000 MW. HCCM was tested in donkey and goat lymphocyte cultures and proved capable of …

Electrophysiology, Cell Calcium, And Mechanisms Of Hepatocyte Volume Regulation, Walid E. Khalbuss

Electronic Theses and Dissertations

The electrophysiologic technique (Reuss, L., Proc. Natl. Acad. Sci. USA 82:6014, 1985) was modified to measure changes in steady-state hepatocyte volume during osmotic stress. Hepatocytes in mouse liver slices were loaded with tetramethylammonium ion (TMA$\sp{+}$) during transient exposure of cells to nystatin. Intracellular TMA$\sp{+}$ activity (a$\sp{\rm i}\sb{\rm TMA}$) was measured with TMA$\sp{+}$-sensitive, double-barreled microelectrodes. Loading hepatocytes with TMA$\sp{+}$ did not change their membrane potential (V$\sb{\rm m}$), and under steady-state conditions a$\sp{\rm i}\sb{\rm TMA}$ remained constant over 4 min in single impalements. Hyperosmotic solutions (50, 100, & 150 mM sucrose added to media) and hyposmotic solutions (sucrose in media reduced by …

Fisheries Research Report No 88 - A Synopsis Of The Biology And The Exploitation Of The Australiasian Pilchard, Sardinops Neopilchardus (Steindachner) Part 1: Biology, W. J. Fletcher

Fisheries Research Reports

There have been a large number of studies which relate to the biology and exploitation of the Australian pilchard, Sardinops neopilchardus. Much of the data, however, are located in journals which are hard to obtain, or in unpublished reports, and theses. With the increase in catch of pil­chards, particularly in Western Australia, a collation of all the available knowledge pertaining to pilchards in Australia and New Zealand was desired to help with the planning of future research into the Western Australian stocks of this species. This report contains all the information located on the biology of Sardinops neopilchardus, a companion …

Grasshoppers In Utah: General Biology, Edward W. Evans

All Archived Publications

No abstract provided.

Intracellular Calcium And The Regulation Of Growth Hormone Release By Growth Hormone-Releasing Factor And Somatostatin In Rat Somatotrophs, Benoit Thierry Lussier

Digitized Theses

The release of growth hormone (GH) from the somatotrophs of the anterior pituitary is under the control of two hypothalamic peptides, GH-releasing factor (GRF) and somatostatin (SRIF), which stimulates and inhibits release respectively. The aim of this study was to explore the role of intracellular Ca{dollar}\sp{lcub}2+{rcub}{dollar} ( (Ca{dollar}\sp{lcub}2+{rcub}{dollar}) {dollar}\sb{lcub}\rm i{rcub}{dollar}) in the regulation of GH release by GRF and SRIF in acutely dispersed purified rat somatotrophs.;The role of extracellular Ca{dollar}\sp{lcub}2+{rcub}{dollar} was studied by assessing the effect of Ca{dollar}\sp{lcub}2+{rcub}{dollar}-free medium and Ca{dollar}\sp{lcub}2+{rcub}{dollar} antagonists on GRF-induced GH release. The fluorescent dye indo-1 was used to measure (Ca{dollar}\sp{lcub}2+{rcub}{dollar}) {dollar}\sb{lcub}\rm i{rcub}{dollar}. Ca{dollar}\sp{lcub}2+{rcub}{dollar} influx was …

Effect Of An Extract Of Superior Ovarian Nerve On Steroidogenesis By Porcine Theca Cells In Vitro, Paul Andrew Morley

Digitized Theses

Ovarian steroidogenesis may be controlled not only by pituitary gonadotropins, but also by ovarian nerves. Nerves reach the ovary via the plexus nerve and the superior ovarian nerve (SON), and innervate the theca cells of all follicles. Thecal androgen biosynthesis is primarily controlled by luteinizing hormone (LH); however, the presence of nerves close to these cells has raised the question of whether nerves can modulate their androgen biosynthesis. The purpose of this study was to develop a porcine theca cell culture system, and to use it to investigate the effects of putative ovarian neurotransmitters and ovarian nerve factors on thecal …

Effects Of Maternal Ethanol Infusion On The Near-Term Ovine Fetus, Graeme Neil Smith

Digitized Theses

Few studies have examined the underlying mechanism(s) of action of ethanol (EtOH) in the developing fetus, especially for non-alcoholic drinking patterns. We have established an experimental protocol using the conscious instrumented near-term pregnant ewe, in which the EtOH-induced suppression of fetal breathing movements (FBM), observed in pregnant women, can be mimicked. The goal of this thesis research was to further characterize the effects of EtOH on the fetus and to elucidate the underlying mechanism(s) of EtOH action, specifically as it pertains to the suppression of FBM.;A previous study by this laboratory demonstrated that maternal intravenous infusion of EtOH (1 g/kg …

Characterization Of A Cytotoxin From Campylobacter Jejuni And Its Role In Pathogenicity, Sangeeta Mahajan

Doctoral Dissertations

Campylobacter jejuni is a major cause worldwide of human gastroenteritis. In this study, the pathogenicity of the organism was examined in fertile hens' eggs and the mortality data and histopathological findings induced by both the organism and bacteria-free filtered broth were similar. The absence in chick embryo tissues of either bacteria or an inflammatory infiltrate suggested a toxic etiology. A protein was obtained from the filtrate by gel electroelution and this was sensitive to heat, pH changes and trypsin treatment and was lethal for the fertile hen's egg. It showed cytotoxic effects in primary chick embryo fibroblast (PCEF), Chinese hamster …

Population Ecology And Feeding Biology Of Nudibranchs In Colonies Of The Hydroid Obelia Geniculata, Walter J. Lambert

Doctoral Dissertations

Kelp blades (Laminaria spp.) with colonies of Obelia geniculata were collected over a 28 month period from Cape Neddick, ME to document the epifaunal community and to determine the possible mechanisms allowing four nudibranch species to coexist. Regression analyses correlated the abundances of epifauna with habitat parameters. The feeding biology of nudibranchs was described. Density manipulations of nudibranchs in pair-wise behavioral interactions tested the effects of interference on the location of nudibranchs in the colony.

Obelia geniculata provides habitat and food for many invertebrate epifauna. The hydroid colony acts as the island for most species. Hydrocauli provide structure to motile …

Factors Affecting The Foraging Ecology Of The Rock Snail Stramonita Haemastoma., Terry David Richardson

LSU Historical Dissertations and Theses

I examined how wave action and predators affect the feeding of the intertidal snail, Stramonita haemastoma. In laboratory wave simulators, the numbers of oysters eaten and tissue mass consumed were reduced compared to controls, but prey size selection was not affected. Handling times and profits (g dry tissue/handling time) of snails feeding on oysters did not differ between snails in wave simulators and controls. Over both treatments, small oysters reduced snail handling times but provided profits similar to that of large oysters. In contrast, field experiments showed that wave exposure was correlated with an increase in the number of oysters …

Factors Involved In Immune Modulation Of Bovine Leukemia Virus Infection., Wanda V. Pool

LSU Historical Dissertations and Theses

Bovine Leukemia Virus (BLV) is an exogenous type-C retrovirus which can induce an aleukemic (AL) stage, a persistent lymphocytotic (PL) stage, or a lymphosarcomatous (LS) stage in infected animals. After experimental infection with BLV, whole blood and serum samples were obtained from 12 holstein heifers for 103 weeks and used to correlate clinical signs (visual observation and white blood cell counts) with changes in humoral immune response (Agar gel immunodiffusion using envelope gp50 as primary antigen, and ELISA and Western immunoblots using whole BLV as antigen). Monoclonal antibodies against BLV envelope gp50 and gag p24 were produced to confirm reactivity …

The Relationship Of Serum Killing, Phagocytosis And Oxidant Production By Bovine Monocyte-Derived Macrophages To Intracellular Survival Of Brucella Abortus., Denise Ida Bounous

LSU Historical Dissertations and Theses

Functional activities of monocyte-derived macrophages and serum killing ability in a population of Brucella abortus-naive cows were evaluated. The ability of these macrophages to phagocytize and control intracellular survival of B.abortus and to produce oxidant was measured. Fresh normal bovine sera killed significantly more B.abortus than reactor serum or fetal bovine serum. When heated to destroy complement, none of the sera were capable of significant killing. The ability of sera from B.abortus-naive cows to kill the bacteria was normally distributed, with all animals within $\pm$ 2 sd of the mean. Phagocytosis of bacteria opsonized with autologous or reactor sera was …

Evaluation Of Selected Pulmonary Function Tests In Resting Thoroughbred Horses Having Reversible, Experimentally Induced Respiratory Dysfunctions., Alan John Guthrie

LSU Historical Dissertations and Theses

The purpose of the first part of this study was to develop computerized techniques for automation of instrument calibration, data collection and calculation of indices of pulmonary mechanical function in resting and exercising horses. The microcomputer system developed enabled a single trained technician to reliably operate the equipment in an equine pulmonary mechanics laboratory. The first experiment investigated the temporal effects of histamine and methacholine aerosols on indices of pulmonary mechanics derived from the linear equation of motion. Data calculated on a breath-by-breath basis were too variable to be reliably modeled. Following application of averaging techniques, the temporal effects of …