Life Sciences Commons^™

Mechanisms Of Retinal Ganglion Cell Development In The Rhesus Macaque, Thomas C. Steineke

Loma Linda University Electronic Theses, Dissertations & Projects

At present, no effective treatments are known for many common neurological problems. For instance, degenerative diseases and central nervous system injuries are two examples of conditions for which few treatment options exist. Studying how neurons develop, and how they establish and maintain connections may provide important insights into potential treatment modalities. To this end, retinal ganglion cell structural development was studied in the fetal rhesus macaque ranging in age from embryonic day (E)60 to El65 (gestation is 165 ± 2 days). Horse radish peroxidase (HRP) retrograde labeling techniques were used to investigate changes in retinal ganglion cell structure during fetal …

Mechanism Of Action Of Pentobarbital Induced Attenuation Of Vascular Smooth Muscle Contraction, Michael R. Samardzija

Loma Linda University Electronic Theses, Dissertations & Projects

Pentobarbital (PB) vasodilates dog mesenteric and cerebral arteries precontracted with KC1, PGF_2α, caffeine or norepinephrine. It is postulated that PB causes this dilation by reducing Ca²⁺ influx as a non-specific Ca²⁺ channel blocker, or decreasing intracellular Ca²⁺ release. We examined PB effects on intracellular Ca²⁺ release (ICR) and extracellular Ca²⁺ influx (ECI) by stimulating Sprague-Dawley rat tail artery rings with either 100 mM KC1, 50 uM phenylephrine (PE), or two different electrical field stimulation (EES) parameters: tetrodotoxin (TTX; 1 uM) sensitive, or perivascular nerve, (NEFS) stimulation (10 Hz, 0.3 ms, 50 V, 30 …

Experimental Culture And Particle Filtration By Asian Moon Scallops, Amusium Pleuronectes, Michael A. Rice, Robert B. Rheault, Miguel S. Perez, Vicente S. Perez

Michael A Rice

Growth rates were determined for scallops (35-75 mm valve height) held in pocket nets and lantern nets at varying densities. The Ford-Walford linear transformation of the von Bertalanffy growth equation was used to allow quantification of food-limited stunting. Pocket nets allowed for greater growth of scallops than did the lantern nets at all stocking densities. The growth rates of scallops in pocket nets, nevertheless, were well below the growth of scallops in the wild. Clearance rates of Caribbean strains of Isochrysis galbana (C-ISO) and Chaetocerous gracilus (C-Cg) were determined for moon scallops. Amusin pleuronectes, in static chambers at 28ºC. The …

Circadian Clock Locus Frequency: Protein Encoded By A Single Open Reading Frame Defines Period Length And Temperature Compensation., Benjamin D. Aronson, Keith A. Johnson, Jay C. Dunlap

Dartmouth Scholarship

The frequency (frq) locus encodes a key component, a state variable, in a cellular oscillator generating circadian rhythmicity. Two transcripts have been mapped to this region, and data presented here are consistent with the existence of a third transcript. Analysis of cDNA clones and clock mutants from this region focuses attention on one transcript encoding a protein. FRQ, which is a central clock component: (i) mutations in all of the semidominant frq alleles are the result of single amino acid substitutions and map to the open reading frame (ORF) encoding FRQ; (ii) deletion of this ORF, or a frameshift mutation …

Short And Long Term Effects Of Proton Microbeam Irradiation : In The Lateral Geniculate Nucleus Of Felis Domesticus, Chad Sherwood Reder

Loma Linda University Electronic Theses, Dissertations & Projects

Little is known of the effects of proton irradiation on neural tissue. A 1.0 mm microbeam was used on the cat lateral geniculate nucleus (LGN) to quantify the short term (< 3 months) and long term (< 9 months) effects of radiation damage. The LGN is a large structure with well defined afferent, efferent, and receptive field properties.

Electrophysiological and histological techniques were used to examine the effects of the microbeam at 60, 40, and 16 Gy, administered as a single bolus. Recordings of light evoked responses in the LGN were obtained using microelectrodes in nine animals within 12 weeks of irradiation, and 6 animals within 36 weeks of irradiation. Receptive fields were mapped onto a tangent screen using standard receptive field techniques. Histological measures included afferent …

An Intramural, Tension-Modulating Reflex In The Rat Caudal Artery, Greg G. Geary

Loma Linda University Electronic Theses, Dissertations & Projects

Electrical field stimulation (EES) of preconstricted arteries causes relaxation. This relaxation is of either neuronal, vascular smooth muscle, and/or endothelial origins. We have shown that EFS-induced relaxation of intact, phenylephrine (PE) preconstricted rat tail artery (RTA) rings was dependent upon the extracellular concentration of Ca++. Inhibiting either nitric oxide (NO) synthesis with N-nitro-L-arginine methyl ester (L-NAME), or the synthesis of cyclic guanosine monophosphate (cGMP) with methylene blue (MB) reduced the EFS-induced relaxation. In addition, inhibition of K_Ca++-dependent hyperpolarization with tetraethylammonium (TEA), or K_ATP hyperpolarization with BaCl₂ or glibenclamide also reduced EFS-induced relaxation. L-arginine reversed the effect …

Inhibition Of Nnk Mutagenesis And Metabolism By Chemopreventive Phytochemicals, Cecil Henry Miller

Loma Linda University Electronic Theses, Dissertations & Projects

Approximately one third of all cancer deaths in the United States can be linked to the use of tobacco products. Cessation of smoking is not always an effective prevention method, especially since nicotine is so addictive. For those individuals who continue to use tobacco products, chemoprevention may be an alternative to reduce their cancer risk. We have investigated the chemopreventive efficacy of five phenolic (catechin, ellagic acid, escletin, esculin and propyl gallate) and five non-phenolic (capsaicin, silymarin, diallyl sulfide, tannic acid, and d-limonene) phytochemicals on tobacco-specific nitrosamine (NNK)-induced mutagenesis and NNK metabolism. In the mutagenesis studies, Salmonella typhimuriumstrain TA1535 …

Summer Activity Cost Of Eared Grebes At Mono Lake, Hugh I. Ellis

Biology: Faculty Scholarship

No abstract provided.

Possible Presence Of Calcium Channel Blocker(S) In Rubia Cordifolia: An Indigenous Medicinal Plant, A H. Gilani, K H. Janbaz, M Zaman, A Lateef, A Suria, H R. Ahmed

Department of Biological & Biomedical Sciences

Crude extract of Rubia cordifolia (RC) was tested in isolated tissue preparations for its possible calcium channel antagonistic activity. RC suppressed the spontaneous contractions of guinea-pig atria, rabbit jejunum and rat uterus in a concentration dependent manner (0.1-3 mg/ml). In rabbit aorta, it inhibited norepinephrine (10 microM) and KCl (80 mM) induced contractions. Replacement of physiological salt solution with calcium free solution abolished the spontaneous movements of rabbit jejunum. However, addition of calcium (25 micrograms/ml) in the tissue bath restored the spontaneous movements. When the tissues were pretreated with plant extract (1 mg/ml) or verapamil (0.5 microgram/ml), addition of calcium …

Multiple Modes Of Asexual Reproduction By Tropical And Subtropical Sea Star Larvae: An Unusual Adaptation For Genet Dispersal And Survival, William Jaeckle

Scholarship

Sea star larvae (Echinodermata: Asteroidea), collected from the subtropical Northwest Atlantic Ocean, exhibited three distinct modes of asexual reproduction. A number of different bipinnariae and brachiolariae reproduced by paratomous cloning of the posterolateral arms. This morphogenesis was identical to that of larvae assignable to the genus Luidia. A second mode of asexual reproduction involves the autotomization of an anterior portion of the preoral lobe. Primary larvae with preoral lobes of varying sizes and free-swimming preoral lobes of various stages of morphological development were simultaneously collected. The free-swimming preoral lobes developed complete digestive systems and ultimately assumed the form of …

Multiple Modes Of Asexual Reproduction By Tropical And Subtropical Sea Star Larvae: An Unusual Adaptation For Genet Dispersal And Survival, William Jaeckle

William Jaeckle

Sea star larvae (Echinodermata: Asteroidea), collected from the subtropical Northwest Atlantic Ocean, exhibited three distinct modes of asexual reproduction. A number of different bipinnariae and brachiolariae reproduced by paratomous cloning of the posterolateral arms. This morphogenesis was identical to that of larvae assignable to the genus Luidia. A second mode of asexual reproduction involves the autotomization of an anterior portion of the preoral lobe. Primary larvae with preoral lobes of varying sizes and free-swimming preoral lobes of various stages of morphological development were simultaneously collected. The free-swimming preoral lobes developed complete digestive systems and ultimately assumed the form of typical …

Rates Of Energy Consumption And Acquisition By Lecithotrophic Larvae Of Bugula Neritina (Bryozoa: Cheilostomata), William Jaeckle

Scholarship

Lecithotrophic larvae of the cheilostome bryozoan, Bugula neritina (L.), lose metamorphic competence 12 to 24 h after release from the maternal zooid. The high respiration rate of newly released larvae (mean=306.3 pmol O₂ larva^-1 h^-1, range= 149.3 to 466.6, n=18 trials, 22.5 °C) from adults collected at Link Port, Fort Pierce, Florida during the winter/spring of 1990-1991 reflects their active swimming behavior. The average energy con¬tent per larva was 15.24 mJ (range: 13.35 to 20.17 mJ ind^-1, n=5 groups). If all cells have an identical energy content and metabolic rate, then 2 and 20% …

Rates Of Energy Consumption And Acquisition By Lecithotrophic Larvae Of Bugula Neritina (Bryozoa: Cheilostomata), William Jaeckle

William Jaeckle

Lecithotrophic larvae of the cheilostome bryozoan, Bugula neritina (L.), lose metamorphic competence 12 to 24 h after release from the maternal zooid. The high respiration rate of newly released larvae (mean=306.3 pmol O2 larva-1 h-1, range= 149.3 to 466.6, n=18 trials, 22.5 °C) from adults collected at Link Port, Fort Pierce, Florida during the winter/spring of 1990-1991 reflects their active swimming behavior. The average energy con¬tent per larva was 15.24 mJ (range: 13.35 to 20.17 mJ ind-1, n=5 groups). If all cells have an identical energy content and metabolic rate, then 2 and 20% of the total en¬ergy content would …

The Effect Of High Intensity Exercise Training Verses Low Intensity Exercise Training On Fractionated Plasma High-Density Lipoprotein Cholesterol, Teresa L. Spate

Masters Theses

Exercise training is thought to result in an elevation of high-density lipoprotein (HDL) and the cardioprotective subfraction HDL{dollar}\sb2{dollar}. Twenty-five healthy women (39 {dollar}\pm{dollar} 7.8 yrs; 70 {dollar}\pm{dollar} 14 kg) walked two miles three times per week for 12 weeks to examine the effect of exercise intensity on the HDL profile. The L.I. group (N = 12) walked at 60% of the heart rate reserve (HRR) and the H.I. group (N = 13) walked at 80% HRR both maintaining the prescribed distance and frequency. A 22% increase in total HDL (from 32 {dollar}\pm{dollar} 6 to 39 {dollar}\pm{dollar} 8 mg/dl) and a …

Uptake Routes Of Benzo[A]Pyrene In An Estuarine Killifish: Cytochrome P4501a Immunohistochemistry Using Whole Fish, Maria Karin Cochran

Dissertations, Theses, and Masters Projects

No abstract provided.

Functional Characterization Of The Electrophoretic Hemoglobin Polymorphism In The Atlantic Croaker (Micropogon Undulatus), Daniel Allen Shelly

Dissertations, Theses, and Masters Projects

No abstract provided.

Frequency Of Attainment Of Plateau In Maximal Oxygen Consumption In Differentially Trained Athletes, Jeffrey Michael Seda

Masters Theses

A plateau in oxygen consumption during exercise testing has been considered a requisite indicator of achievement of true maximal oxygen consumption. The wide range of reported percentages of subjects revealing a plateau (7 to 80 percent) indicates that closer analysis of factors that may influence plateau attainment is necessary. This study examined the frequency of plateau attainment in two groups of differentially trained subjects. One group (TR) of 12 males (ages 18-36) were trained runners and the other group (WL) of 12 males (ages 18-31) consisted of trained weight lifters. The subjects participated in a series of maximal exercise tests …

Can Critical Power Predict And Monitor Swimming Performance?, Michelle L. Stoppenhagen-Noll

Masters Theses

The purpose of this study was to determine if critical power (CP) can be used to predict and monitor swimming performance. Fifteen female collegiate swimmers from Eastern Illinois University volunteered as subjects for this study. CP was measured on an arm ergometer. Freestyle performances in the 50 and 100 yard distances were also measured. All three tests were measured both pre- and post-season. Results indicated that CP can predict performance in the 50 and 100 yard freestyle swims. Those with higher CP will swim faster. CP can monitor improvement in 50 yard times. CP is not a good indicator of …