Life Sciences Commons^™

Morphometric, Isozyme And Random Amplified Polymorphic Dna (Rapd) : Analysis Of Sarotherodon Mossambicus Populations In Java, Indonesia, Yoedono Sovyanhadi

Loma Linda University Electronic Theses, Dissertations & Projects

The tilapia fish Sarotherodon mossambicus (Teleostei, Cichlidae) is an important protein source for Indonesians, is a strong competitor with some endemic species and .readily hybridizes with other tilapias. A base line assessment of the present genetic diversity of these populations in Indonesia was conducted to facilitate the management of this species. This study compared the effectiveness of the 3 techniques (morphometric, isozyme and RAPD) in revealing differences within and among 9 Javanese populations. The data were also used to estimate the rate of divergence among the populations.

Morphometric analysis showed significant size and shape differences among the populations. Isozyme and …

Active Inhibition Of T Cell Proliferation By Monocytes, Dean Anthony Lee

Loma Linda University Electronic Theses, Dissertations & Projects

Monoclonal antibodies (mAb) to MHC class II molecules (anti-class II mAb) have been well described in their ability to inhibit T cell activation. The most current model is that anti-class II mAb interfere directly with the T cell receptor-major histocompatibility complex crosslinking which is necessary for T cell activation. The anti-CD3 mAb, OKT3, is an MHC class II molecule-independent mitogen which causes T cell activation by direct ligation of the TCR-CD3 complex. OKT3 and a panel of anti-class II mAb were used to dissect the individual roles played by these two receptors in activation and inhibition of peripheral blood mononuclear …

The Aerobic Metabolism And Behavior Of The Burrow-Dwelling Mantis Shrimp, Hemisquilla Ensigera Californiensis, Jason Jospeh Cassista

Loma Linda University Electronic Theses, Dissertations & Projects

The predatory stomatopod Hemisquilla ensigera californiensiswas captured at 10-20 m depths off California and transferred to an observation tank with artificial burrows similar to those observed in the field. The animals were maintained under a 1OL:140 light-dark cycle and monitored on a 24-hour basis using a time-lapse video recorder. Infrared lamps were used for observations within the burrow and at night. Metabolic rates, as a function of oxygen tension, were measured in respirometry chambers using polarographic oxygen electrodes.

This species is a near complete oxyconformer, so aerobic metabolism is strongly depressed at low oxygen levels, yet the animals remained …

Evaluation Of Nitric Oxide In Respiratory Distress Syndrome, Kimberly S. Myruski

Loma Linda University Electronic Theses, Dissertations & Projects

Little is known of the effects of low concentrations of inhaled nitric oxide (NO) on pulmonary mechanics and lung volumes in premature newborn infants with lung disease. Cardiopulmonary function tests including blood gas analyses were obtained from eleven premature lamb models with respiratory distress syndrome to determine if compliance, airways resistance, tidal volume, functional residual capacity, and gas exchange were affected. The effect of inhaled NO on the direction of shunting through the ductus arteriosus was determined using echocardiography.

Twin lambs were cannulated with arterial and venous catheters and intubated with an endotracheal tube before delivery on gestational day 126-130 …

Alveolar Bone And Cementum Regeneration Following Periodontal Reconstructive Therapy : A Review Of Histologic Observations In Man And Experimental Animals, Karen E. Rodden

Loma Linda University Electronic Theses, Dissertations & Projects

Periodontal regeneration includes the formation of both alveolar bone and cementum. Studies reporting histologic evidence of healing following periodontal reconstructive therapy were reviewed to determine whether regeneration of these structures improves with increasing healing interval, and whether they regenerate independently or whether regeneration of one structure is dependent upon regeneration of the other. Additionally, the review addresses whether specific reconstructive modalities predictably yield increased amounts of regeneration. Differences in regenerative potential between humans, nonhuman primates, and canines were also examined. Results of over a decade of studies of periodontal reconstructive therapy were tabulated by family (human, nonhuman primate, and canine) …

Developmental Regulation Of The Murine Cd4 Gene, Rhonda Kay Hansen

Loma Linda University Electronic Theses, Dissertations & Projects

CD4 is a membrane bound glycoprotein that plays an important role in T cell development and activation. An extensive analysis of the CD4 locus identified potential transcriptional control elements located 5' of the promoter and within the first intron. Since the molecular mechanism for the control of CD4 expression during T cell development had not been determined, it is the focus of this dissertation. A series of recombinant DNA constructs were made to determine the contribution of putative transcriptional control elements in regard to CD4 expression, and to identify elements being used to control CD4 expression during T cell development. …

A Model Of Cytomegalovirus Association With The Development Of Heart Graft Atherosclerosis, Evan Skowronski

Loma Linda University Electronic Theses, Dissertations & Projects

The development of graft atherosclerosis in heart transplant recipients has been associated with the development of post-transplant cytomegalovirus infection. The mechanism of this involvement, however, remains unclear. I undertook a study to determine the role of cytomegalovirus in the development of graft atherosclerosis. First, a rapid method of detecting cytomegalovirus based on capillary polymerase chain reaction and gel electrophoresis was employed to determine the presence of cytomegalovirus in a wide variety of clinical samples. Detection of cytomegalovirus is a lengthy procedure under normal conditions, and timely detection of cytomegalovirus in transplant recipients may allow intervention early enough to block the …

Ornithine Decarboxylase And Polyamines In Perinatal Hypoxia, Satyaseelan Packianathan

Loma Linda University Electronic Theses, Dissertations & Projects

Hypoxic and hypoxic/ischemic episodes contribute to various neurological aberrations, learning disabilities, et cetera in surviving infants. Despite major advances in understanding the pathophysiology of hypoxia, the cellular basis for hypoxic-mediated injury remains poorly understood. In addition, the role of developmentally essential enzymes vis á vis their contributions, or lack thereof, to hypoxic-mediated injury has not been adequately investigated. In the series of studies comprising this dissertation, we tested the hypothesis that acute and/or chronic hypoxia affect the activity of omithine decarboxylase (ODC; E.C. 4.1.1.17), the developmentally essential enzyme in polyamine biosynthesis, in the fetal and newborn rat brain. Fetal and …

Periodontal Repair In Dogs : Evaluation Of Rhbmp-2 Carriers, Lauralee Nygaard

Loma Linda University Electronic Theses, Dissertations & Projects

This study evaluated candidate carriers for recombinant human bone morphogenic protein-2 (rhBMP-2) in periodontal reconstructive surgery.

Canine demineralized bone matrix (DBM), bovine inorganic crystallene bone matrix (Bio-Oss), bovine derived microfibrillar collagen matrix (Helistat), poly (D,L-lactide-coglycolide) micropaiticles (PLGA), and polylactic acid granules (Drilac) were used with rhBMP-2 (20 (µg/100 µl implant volume) in routine critical size canine supraalveolar periodontal defects. Contralateral defects in six beagle dogs were randomly assigned to receive: DBM/rhBMP-2, DBM-control, Bio-Oss/rhBMP-2, Helistat/rhBMP-2, PLGA/rhBMP-2, or Drilac/rhBMP-2, all with autologous blood except for Helistat and PLGA. Animals were sacrificed eight weeks post-surgery and block sections of the defects were processed …

Maturational Changes In Cerebrovascular Ca2+ In Hypoxia, Shelley D. Zurcher

Loma Linda University Electronic Theses, Dissertations & Projects

The clinical consequences of hypoxic cerebrovascular insults in the neonate, can be severe. It would therefore be valuable to understand the mechanisms of hypoxia-induced cerebrovasodilation. These studies were done in ovine middle cerebral and common carotid arteries to help elucidate the mechanisms through which calcium handling is involved in hypoxic cerebral vasodilation, comparing newborns and adults. The present studies demonstrate that calcium sensitivity (measured by the pD2) and the maximum contractile response to calcium increased with maturation. In addition, hypoxia depressed the maximum response to calcium and this effect was greater in adult than in newborn arteries. These results suggest …

Regulation Of The Insulin-Like Growth Factor System By Retinoic Acid In Human Osteoblast Cells, Yuehua Zhou

Loma Linda University Electronic Theses, Dissertations & Projects

Retinoic acid (RA) is an important regulator of growth and differentiation in many cell types, including bone. However, its effects on human osteoblast cell growth and differentiation have not been well studied. Therefore, I investigated the effect of RA on proliferation and differentiation of normal human bone cells (HBCs) and human osteosarcoma, SaOS-2 cells. RA decreased baseline as well as serum-stimulated proliferation in normal HBCs. To determine the effect of RA on differentiation, expression of several osteoblastic differentiation markers were studied. RA decreased type I procollagen mRNA levels and l,25(OH)₂D₃-stimulated osteocalcin and alkaline phosphatase (ALP) mRNA …

Experimental Peri-Implant Tissue Breakdown In Rhesus Monkeys, Oliver Hanisch

Loma Linda University Electronic Theses, Dissertations & Projects

The aim of this investigation was to characterize peri-implant tissue breakdown following ligature-induced plaque accumulation around osseointegrated implants in the rhesus monkey. Two hydroxyapatite-coated cylindrical implants were inserted bilaterally in the second premolar and first molar region of both mandible and maxilla in four non-human primates (Macaca mulatto). The implants were left submerged to osseointegrate for one year. Eight weeks after healing abutment connection, a two-month plaque control program was initiated. At the end of this period, clinical and radiographic recordings were carried out, and peri-implant subgingival microbial samples were obtained (baseline). Subsequently, cotton ligatures were placed around …

Modulation Of Neutrophil Functions By Neurotransmitters Implicated In Stress, Chok Ping Wan

Loma Linda University Electronic Theses, Dissertations & Projects

Stress has long been implicated in immune modulation. People under chronic stress have no change in the circulating basal levels of catecholamines while plasma levels of neuropeptide Y (NPY) are significantly increased. Sympathetic nerve fibers with NPY have been found to innervate immune organs. It was hypothesized that NPY might be a mediator in immune modulation in people under chronic stress. Human neutrophils were used as a model to study the effects of NPY alone or together with norepinephrine on the immune system. We now report that NPY modulates oxidative burst (OB) triggered by zymosan in human neutrophils while it …