Life Sciences Commons^™

Effects Of Dietary Calcium And Fasting On Osteoclast Recession And Recruitment In Calcium Deficient Rats, Kenneth R. Wright

Loma Linda University Electronic Theses, Dissertations & Projects

The osteoclast, a multinucleated giant cell, has as its role the resorption of bone matrix with consequent release of calcium. The osteoclast is thought to derive from a pluripotent stem cell which also gives rise to monocytes and macrophages. The development, activation, and inhibition of osteoclasts are influenced by a number of systemic and local factors. The release of these factors is influenced by changes in the dietary status of the animal. Calcium deficiency is known to stimulate the recruitment and activity of large numbers of osteoclasts. These osteoclasts can subsequently be inhibited by increasing dietary calcium intake. Disappearance of …

The Effect Of Trimethyltin On The Cholinergic System Of The Rat Hippocampus, Richard L. Cannon

Electronic Theses and Dissertations

Trimethyltin (TMT) is a neurotoxin occurring in the environment. Exposure to (TMT) is known to destroy specific neuronal components of the hippocampus in the rat and to cause clinical symptoms in exposed humans, including mnemonic deficits, that indicate hippocampal involvement. In addition to hippocampal cell loss TMT causes significant increases in cholinergic markers such as acetylcholinesterase (AChE) stain density and choline acetyltransferase (ChAT) activity in the hippocampus of rats. However, despite these observations the effect of TMT on hippocampal cholinergic system has not been investigated in detail. The purpose of the present study was to elucidate more fully the consequences …

Neurophysiologic Bases For Abnormal Muscle Coactivation Patterns In Hemiparetic Stroke, Julius P.A. Dewald

Loma Linda University Electronic Theses, Dissertations & Projects

To study disturbed muscle activation patterns in hemiparetic stroke, the EMG activity in spastic-paretic and contralateral elbow muscles of 10 stroke subjects were compared during graded directionally varying voluntary isometric contractions. We observed significant shifts in the peak EMG angle and increases in the angular range of EMG activity in the impaired upper limb. Furthermore, we observed stereotypic coactivation of many muscles acting at the same joint or at different joints across all subjects.

The effect of elbow angle changes on muscle coactivation patterns was studied by examining isometric torque-angle relations under passive and active conditions in 8 stroke subjects. …

Identification And Characterization Of Possible Multiple Binding Sites For ((3)H)8-Oh-Dpat In The Hippocampus, Dawna Lea Evans

Masters Theses

No abstract provided.

Changes In Intracellular Chloride During Osmotic Stress And L-Alanine Uptake In Mouse Hepatocytes, Kening Wang

Electronic Theses and Dissertations

A stable intracellular ionic environment is necessary for hepatocytes to function normally. Thus, during hypotonic shock or L-alanine uptake, hepatocytes swell and then exhibit a regulatory volume decrease (RVD), which comprises an increase in K$\sp+$ conductance (G$\sb{\rm K}$), an increased K$\sp+$ efflux, and a hyperpolarization of transmembrane potential (V$\sb{\rm m}$). Since hepatocyte intracellular Cl$\sp-$ has been demonstrated to distribute passively with V$\sb{\rm m}$, this study is designed to test the hypothesis that the hypotonic shock- or L-alanine uptake-induced hyperpolarization of V$\sb{\rm m}$ might provide an electromotive force for the efflux of hepatocyte intracellular Cl$\sp-$, which in turn would contribute osmotically …

The Effects Of Post-Event Massage Therapy On Multistage Ultraendurance Cycling, Tracey Hodges Drews

Human Movement Studies & Special Education Theses & Dissertations

Post-event massage therapy has been proposed to hasten muscle recovery and improve ensuing performance in multistage ultraendurance cycling events. Six elite male cyclists competed in two 4·d stage races of 161 kmd^·1 on a computerized race simulator over challenging terrain in a controlled laboratory environment with an average completion time of 275 ± 28 min. In a crossover experimental design, subjects received either 30 min post-event massage therapy or a 30 min inactivated diathermy treatment serving as a blind placebo after each 161 km race. The subjects repeated the 4·d, 161 km·d^·1 event 18d later receiving alternate post-event …

Transforming Growth Factor-Beta 1 Expression In Developing Ovine Teeth As Visualized By In Situ Hybridization, Søren Jepsen

Loma Linda University Electronic Theses, Dissertations & Projects

Recently we demonstrated that human dentin contained relatively high amounts of transforming growth factor beta (TGF-ß) and proposed that dentin TGF-ß originated from odontoblasts. Because of the suggested role of TGF-ß in mediating cellular interactions in dental cell development by paracrine mechanisms, we studied the expression of TGF-ß message in developing teeth by in situ hybridization. 5 µm serial sections of neonatal sheep mandibular third molars that had been fixed in glutaraldehyde and paraffin-embedded were used for in situ analysis. An [³⁵S]-labeled cRNA probe, complementary to TGF-ß1 mRNA, was constructed from human TGF-ß1 cDNA. Northern analysis of total …

Development Of Periapical Lesions In Immunosuppressed Rats, Phillip A. Waterman Jr.

Loma Linda University Electronic Theses, Dissertations & Projects

The pathogenesis of periapical lesions is the interaction of the oral flora with the existing host defenses. The role of bacteria has been established in endodontic disease but the contribution of the host defenses in periapical lesion formation is less clear. The purpose of this study was to compare periapical lesion development in immunosuppressed rats with that in normal rats. Thirty-five, eight-week old Sprague-Dawley rats were equally divided into seven groups. Groups 1, 2, and 3 were given weekly injections of Cytoxan, an immunosuppressive agent. Groups 4, 5, and 6 received no immunosuppressive therapy. Group 7 served as a control, …

The R Value At Vo2 Max During Maximal Graded Exercise Treadmill Tests Of Coronary Artery Diseased And Nondiseased Subjects, Sherry S. Williams

Masters Theses

This study examined the R value at VO2 max during maximal graded treadmill exercise tests to determine if it was a reliable indicator of VO2 max and could therefore be used as a test termination criterion. The subjects in this study were 160 coronary artery diseased (CAD) patients and 170 nondiseased individuals. Data were collected from existing stress test records. The R value was also analyzed to determine if proportions of diseased and nondiseased subjects were the same. The time it took 100 CAD patients to reach VO2 max and exhaustion once R rose above 1.00 was also examined.

The …

Fixed-Ratio Size As A Determinant Of The Development Of Tolerance To Morphine, Mark J. Nickel

Masters Theses

The acute and chronic effects of morphine were examined in pigeons exposed to a multiple schedule with fixed ratio 5, 25, and 125 components. Acute exposure to morphine (0.56-10.0 mg/kg) resulted in rate reductions under each component when the dose was 1 mg/kg or higher. With chronic exposure to 5.6 mg/kg, tolerance to the rate-reducing effects of morphine was evident under each fixed ratio component. The development of tolerance was determined to some extent by fixed-ratio size, a result similar to earlier findings with cocaine.

F Response Frequency For The Median And Ulnar Nerves In A Normal Population, Patricia J. Killea

Rehabilitation Sciences Theses & Dissertations

The F wave or F response results form the recurrent discharge of antidromically activated anterior horn cells. F response latency represents an impulse which travels to and from the spinal cord through the central segment of a nerve. Study of the F wave is commonly done to assess proximal conduction in motor nerves, to measure motor nerve conduction velocity over a longer pathway than in orthodromic motor studies, and to assess motor neuron excitability. F response characteristics less commonly studied include duration, chronodispersion, shape, amplitude, and frequency. The primary purpose of this study was to determine F response frequencies of …

Biochemical Investigation Of Gout And Its Familial Incidences, Chin-Ling Hsu

Chemistry & Biochemistry Theses & Dissertations

Gout is a chronic metabolic disorder caused by deposition of uric acid on the joint. It is categorized into two types: primary and secondary. Primary gout is uric acid overproduction, caused by excessive synthesis of the purine precursors. Secondary gout occurs also as the result of overproduction or decreased renal excretion of uric acid resulting from other disease processes or medication.

The two purine bases, hypoxanthine and xanthine, liberated from ribosides by the action of nucleoside phosphorylase, are degraded to uric acid as the final excretory product in the purine degradation pathway. Hypoxanthine and xanthine are the physiological substrates of …

Kinetic Characterization Of A Recombinant C-Terminal Mutant Of Reverse Transcriptase From The Human Immunodeficiency Virus, Thomas S. Heard

Chemistry & Biochemistry Theses & Dissertations

The human immunodeficiency virus (HIV) reverse transcriptase (RT) (EC 2.7.7.49) is the central replication enzyme for HIV. In general, the kinetic mechanism for this and all other polymerases involves the ordered binding of two substrates: a primer-template (PT) followed by a deoxyribonucleoside triphosphate (dNTP). Previous investigations prompted this research when it was discovered that the substrate dNTP, in absence of PT, could protect a recombinant c-terminal mutant HIV-1 RT from inhibition by pyridoxal-5'-monophosphate (PLP), an active-site dNTP inhibitor. In contrast, the non-mutant recombinant HIV-1 RT required both substrates for protection from PLP inhibition. This investigation sought to determine if this …

New In Vivo And In Vitro Techniques For Quantification Of Lateral Force Levels That Cause Implants To Fail : A Progress Report On Monkey Research, V. Leroy Leggitt

Loma Linda University Electronic Theses, Dissertations & Projects

Two new techniques for quantification of forces generated by an expansion screw apparatus placed between pairs of cylindrical endosseous titanium implants are described, along with preliminary data gained from their use in Macaca rhesus monkeys. Strain gages were bonded to the expansion apparatus and were calibrated either directly by micro load cell, or indirectly by Instron Machine to reflect the applied force.

Immediate loads of up to 6 kilograms have been applied to the implants with no increase in mobility as verified by a Periotest device. No previous studies on the orthodontic uses of implants have evaluated in vivo forces …

Cortisol In The Ovine Fetus : Its Regulation And Role In Parturition, Ede Marie Apostolakis

Loma Linda University Electronic Theses, Dissertations & Projects

In fetal sheep, circulating cortisol increase during late gestation to abruptly rise 72 hours preceding birth. Although the surge in cortisol is thought to initiate the endocrine cascade which triggers parturition, it is not known what drives the prepartum rise in fetal cortisol. The first study tested the hypothesis that basal cortisol secretion is regulated by adrenocorticotropin (ACTH) which in turn, is controlled by arginine vasopressin (AVP). The fetus challenged with AVP increased plasma ACTH and cortisol concentrations. Pretreatment with an AVP V₁ receptor antagonist blocked AVP-induced plasma ACTH cortisol but failed to alter basal ACTH or cortisol. To …

Modulation Of Rat Hepatic S9-Dependent Mutagenesis, Dna Binding, And Metabolism Of Aflatoxin B1 And Benzo[A]Pyrene By Four Chinese Medicinal Herbs, Brian Yuen Yau Wong

Loma Linda University Electronic Theses, Dissertations & Projects

Extracts of the herbs Oldenlandia diffusa (OD) and Scutellaria barbata (SB) have been used in traditional Chinese medicine for treating liver, lung and rectal tumors while extracts of Astragalus membranaceus (AM) and Ligustrum lucidum (LL) are often used as adjuncts in cancer therapy. In this study, we determined the effects of aqueous extracts of these four herbs on aflatoxin B₁ (AFB₁) benzo[a]pyrene (BaP), benzo[a]pyrene 7,8-dihydrodiol (BaP 7,8-DHD) and benzo[a]pyrene 7,8-dihydrodiol-9,10-epoxide (BPDE)-induced mutagenesis, mediated by enzymes in rat hepatic 9000 x g supernatant (S9), in Salmonella typhimurium TA100. We also studied the effects of these four herbs on …

Plasticity Of The Gnrh Neuronal System During Sexual Maturation Of The Male Djungarian Hamster, Kevin L. Buchanan

Loma Linda University Electronic Theses, Dissertations & Projects

Onset of puberty in male Djungarian hamsters is characterized by increased pituitary gonadotropin secretion and testes maturation, and is controlled by neurons within the brain which secrete gonadotropin-releasing hormone (GnRH). Puberty is associated with increased numbers of morphologically unipolar, but not bipolar, GnRH neurons in the medial preoptic area (MPOA) and diagonal band of Broca (DBB). To test the hypothesis that delayed sexual maturation arrests this increase, males were exposed to short days or administered melatonin. Males with delayed puberty had significantly fewer unipolar GnRH neuron numbers in the MPOA and DBB comparable to pubertal controls in long days. Unipolar …

An Evaluation Of Surface Enamel Damage Following The Debonding Of Ceramic Brackets : A Follow-Up Study, B. Scott Hood

Loma Linda University Electronic Theses, Dissertations & Projects

To evaluate surface enamel damage after debonding ceramic brackets using their manufacturer's recommended methods, sixty four bicuspid teeth were bonded with three different types of ceramic brackets and one type of metal bracket. All the brackets tested utilized mechanical retention only. The brackets were debonded in the mouth seven to ten days after bonding, extracted and evaluated with a scanning electron microscope. The study concluded that: 1) all brackets alter the surface enamel, 2) there is a significant difference in surface enamel damage between the metal bracket and the ceramic brackets utilizing a tensile debonding method, 3) there is no …

The Effect Of Electrical Stimulation Of The Dorsal Raphe Nucleus On Local Cerebral Glucose Metabolism And Epileptogenesis In The Rat, Clifford C. Douglas

Loma Linda University Electronic Theses, Dissertations & Projects

Anatomic connections between the dorsal raphé and the hippocampus have been described in the literature; however, the understanding of the functional importance of these connections is not complete. In these studies the "functional" raphé-hippocampal pathway was elucidated first by the 2-deoxy-d-glucose (2-DG) method, and second by the effect of dorsal raphé electrical stimulation on kindled seizure in the rat. In the 2-DG study, differences in local rates of cerebral glucose metabolism were quantified. The pattern of 2-DG uptake differed significantly from controls (animals with electrodes placed and not receiving an electrical stimulus) and subjects stimulated in the pontine oral reticular …

Molecular And Cellular Analysis Of Chlamydia Trachomatis: Persistence And Reactivation, Kimberly R. Tau

Electronic Theses and Dissertations

Chlamydia trachomatis (CT) is the most prevalent sexually-transmitted infection in the United States. It has been suggested that CT infections can become latent. This has not been substantiated. CT persistence was examined at the molecular and cellular level in vitro and in vivo. Penicillin treatment of CT in vitro results in abnormal inclusions and reduced recovery of infectious CT. Penicillin did not inhibit initial stages of infection, but did downregulate CT rRNA levels after 25 hours post-inoculation (p.i.). DNA amplification was employed to differentiate between a resolved infection and a persistent one. Utilizing a primer pair that amplified a 144 …

Characterization Of A Novel Prostate Tumor-Associated Antigen, Grayson B. Lipford

Theses and Dissertations in Biomedical Sciences

The murine monoclonal antibodies (MAb) TURP-27 and HNK-1 have been shown to detect antigens that are heavily expressed by benign prostatic hyperplasia (BPH) and carcinoma of the prostate (CaP). Western blot analysis of prostate extracts, showed that MAb TURP-27 and MAb HNK-1 bound glycoproteins of 180, 140, 120, 100, 90 and 69 kDa. Studies have shown that the HNK-1 carbohydrate epitope may be involved in cell adhesion and that it is a component of several characterized adhesion proteins. TURP-27 was found to bind at least three of these adhesion proteins: neural cell adhesion molecules (N-CAM), myelin-associated glycoprotein (MAG) and a …

Biodegradation Of Crude Oil By Marine Higher Fungi, Brian J. Dyer

Biological Sciences Theses & Dissertations

Four experiments were performed to determine the ability of marine higher fungi to grow in and degrade crude oil. Eight species, previously determined to be hydrocarbonoclastic, were grown in artificial sea water medium (ASM) and southern Louisiana crude oil. The dry mycelial weights were measured and consumption of crude oil was measured gravimetrically. The two species with the best growth, Corollospora maritima and Zalerion maritimum, were grown in ASM containing crude oil spiked with three known hydrocarbons. To this was added glucose (0.15%) and incubated 49 days to test for possible cometabolism of hydrocarbons. Hydrocarbons remaining in the growth …

The Expression And Regulation Of The Hsdk Genes Of Escherichia Coli K-12, Ainu Parkash

Loma Linda University Electronic Theses, Dissertations & Projects

The DNA restriction and modification (R-M) genes in bacteria play a defensive role in the organism, offering protection to the host from invaders such as bacteriophages. The expression of these genes in E. coli K-12 had not previously been studied due to the complexity of the EcoK R-M enzymes. The use of lacZ gene fusion techniques allowed studies of the expression of the hsdK genes for the first time. Operon fusions of Mu(/ac) to the hsdK genes show that the two hsdK promoters, p _res and p _mod, are weak (50 Miller units) and that …

The Effect Of Experimental Alterations In Excess Weight On Vertical Jump Performance, Bobbi Becker

Dissertations and Theses @ UNI

The purpose of this study was to investigate the effect of experimental alterations in relatively small amounts of excess weight on vertical jump height. The objective was to use the consequences of changes in body weight on vertical jump performance. The subjects were 19 Division I college volleyball players from the University of Northern Iowa. The mean value for age was 20.04 years, the mean height was 176.2 cm, the mean weight was 71.58 kg, and the mean percentage of body fat was 22.60% for all subjects. Each subject was tested under six weight conditions: (a) normal body weight, (b) …