Physiology Commons^™

Characterization Of Hsd::Mudx128 Operon Fusion Mutant Of Escherichia Coli K-12, Marjorie Ann T. Reyno

Loma Linda University Electronic Theses, Dissertations & Projects

The study of the regulation of gene expression in complex genes can be facilitated by the use of operon fusions which place a well characterized lacZ gene under the control of a promoter of interest. An hsd::MudX128 operon fusion mutant of E. coli K-12 isolated by Prakash (1986) was observed to have a high β-galactosidase activity (1000 units), ten to twenty times higher than other hsd::MudX mutants. This β-galactosidase activity was suppressed to a very low level (25 units) by the introduction of an F’ plasmid, F'101, which carries the 98 min to 2 min region of the …

Enhancement Of Intratumor Antibody Distribution With A Bifunctional Antibody Delivery System And With Hyperthermia, Karen Lynn King

Loma Linda University Electronic Theses, Dissertations & Projects

The intratumor distribution of a new monoclonal antibody-hapten-based delivery system was examined. From two marine antibodies, Hybritech, Inc. has developed a bifunctional antibody (BPA) with specificities against CEA (ZCE-025 or GEM 231) and against one of two derivatives of [¹¹¹In]-benzyl-EDTA (CHA 255), EOTUBE or BLEDTA IV, to form ZCE/CHA or CEM/CHA. BFA accumulates in CEA-expressing tissue and clears from non-antigenic tissues prior to administration of an [¹¹¹In]-hapten.

Using five groups of nude mice bearing human colon tumor xenografts (T380), we evaluated different carriers of [¹¹¹In]-EOTUBE to prelocalized ZCE/CHA. We administered all antibodies and haptens …

Regulation Of Epidermal Growth Factor Receptor Synthesis By Retinoic Acid And Dexamethasone, Kerby C. Oberg

Loma Linda University Electronic Theses, Dissertations & Projects

Fetal rat lung (FRL) cells incubated in the presence of retinoic acid or dexamethasone exhibit altered ¹²⁵I-epidermal growth factor (EOF) binding capacity. Retinoic acid enhances ¹²⁵I-EGF binding 3-fold following 24 hours of 37° incubation. In contrast, FRL cells incubated in the presence of dexamethasone display a 2-fold reduction in ¹²⁵I-EGF binding capacity. The change in binding capacity, induced by either hormone, was due to alterations in the average number of receptors per cell as determined by Scatchard analysis of ¹²⁵I-EGF binding. In the absence of retinoic acid or dexamethasone, FRL cells were calculated to have approximately …

Autonomic Nervous System And Cholesterol Transport, Yuan-Line Hung

Loma Linda University Electronic Theses, Dissertations & Projects

The effect of autonomic nervous system on cholesterol transport is of clinical interest because the relationship between lipoprotein metabolism and atherogenesis is expressed in coronary artery disease.

Generally speaking, beta blockers increase serum VLDL level but decrease both HDL and HDL₂ cholesterol levels without affecting the LDL in humans. We are unaware of reports concerning the effects of metoprolol on lipoprotein metabolism nor comparison of the effects of metoprolol and propranolol in the unhandled rat model. In part I we employed the unhandled rats to compared the effects of these 2 drugs administered with the drinking water in order …

Maternal And Fetal Responses To Long-Term Hypoxemia In Sheep, Benjamin L. Siu

Loma Linda University Electronic Theses, Dissertations & Projects

The effect of acute or short term hypoxia on fetal and maternal cardiovascular hemodynamics has been well known, however, little is known about the effect of long term hypoxemia. To determine the animals hemodynamic responses to this stress we studied 3 groups of animals 1) pregnant ewes (n=20) 110 to 115 days of gestation, subjected to hypoxia for up to 28 days, 2) pregnant ewes (n=4) which served as normoxic controls, and 3) non pregnant ewes (n=6) subjected to hypoxemia for up to 28 days. We measured maternal and fetal mean arterial pressure (Bp), heart rate (HR), arterial PO_{2 …}

The Prenatal Development Of The "Synaptic" Structures In The Guinea Pig Pineal Gland, Zhongrong Luo

Loma Linda University Electronic Theses, Dissertations & Projects

Pineal "synaptic" ribbons are a heterogeneous population of organelles. In addition to "synaptic" ribbons (SR) sensu stricto, which are electron-dense rods, "synaptic" spherules (SS) and intermediate forms (IMF) are present. The SS are electron-dense spherical structures, the diameter of which is two to three times the width of the SR. The IMF appear as irregularly formed structures. The SR, SS and IMF are surrounded by electron-lucent vesicles. Their function and origin are unknown and also a knowledge of their prenatal development is lacking. In order to gain an insight into the development of the "synaptic structures, the pineal glands …

Effect Of Dietary Factors On Mutagenesis, Metabolism, And Binding To Dna Of Benzo [A] Pyrene And Benzo [A] Pyrene 7, 8-Dihydrodiol, Robin E. Vance

Loma Linda University Electronic Theses, Dissertations & Projects

Ellagic acid (EA), a naturally occurring plant phenol, at concentrations of 5 to 50 pg/plate, inhibited rat liver S9 protein dependent benzo[a]pyrene (B[a]P)-induced mutagenesis in Salmonella typhimurium TA 100 by 30-81% and B[a]P 7,8-dihydrodiol (DHD)-induced mutagenesis by 29 to 75%. EA (5-40 juM) did not significantly affect the metabolism of B[a]P or B[a]P 7,8-DHD as determined by high performance liquid chromatographic analysis of the organosoluble fraction and by the quantification of watersoluble conjugates. At these concentrations EA inhibited 3 3 the covalent binding of [ H] B[a]P and [ H] B[a]P 7,8-DHD metabolites to calf thymus DNA by 5 to …

An Analysis Of Protein-Ligand Interactions For Enzyme Ii-Mannitol From Escherichia Coli, Brent Lee Wood

Loma Linda University Electronic Theses, Dissertations & Projects

Enzyme II^mtl of Escherichia coli was purified from mtlA-overexpressing E. coli strain LJ1112 extraction of isolated membranes with deoxycholate, followed by hexyl agarose and ω-amino hexyl agarose chromatography in Lubrol PX. A 10-fold increase in total pure protein and 2.5-fold increase in specific activity over previously reported procedures was obtained. Tryptic fragments of Enzyme II^mtl were also purified and identified as the membrane and cytoplasmic domains by protein sequencing and SDS-PAGE. The fluorescence spectrum of Enzyme II^mtl suggested that two populations of tryptophan residues existed with emission maxima at 322 and 344 nm, corresponding to buried …

Age-Related Changes In Meissner Corpuscles Of Diabetic Mice As Observed By Electron Microscopy, Vicky R. Ras

Loma Linda University Electronic Theses, Dissertations & Projects

Light touch and low-frequency vibration sense are often impaired in diabetic patients. Meissner corpuscles are distally located mechanoreceptors that respond to these stimuli. Peripheral sensory neuropathy in diabetes progresses from distal to proximal, therefore, Meissner corpuscles are ideally suited to study diabetic neuropathy in the C57BL/Ks (db/db) mouse.

Corpuscles from the forepaw digital pads of 9 diabetic and 9 nondiabetic littermates were studied by electron microscopy. These were divided into 3 age groups; 2.5 months, 10 months, and 17 months old.

Ultrastructural changes observed within various receptor components were myelin figures, multivesicular bodies, vacuoles, basal lamina duplication, abnormal and enlarged …

A Descriptive Catalog Of Dimming Cells In The Purple Shore Crab Hemigrapsus Nudus, Eugene Pak

Loma Linda University Electronic Theses, Dissertations & Projects

A population of cells responsive to the decrease or dimming of light was identified in the Purple shore crab Hemigrapsus nudus. Extracellular pin electrode recordings from the optic nerve tract measured responses to decremental changes in relative light levels over the range 40 to 0.08 lux. The observed activity revealed that these dimming cells could respond over this entire range. A catalog detailing the response characteristics for each of the thirty dimming cells in the study was generated. The parameters measured the receptive field size; response to mechanoreceptive tactile stimuli; response to abrupt On or Off light level changes; …

Signal Processing In Bacterial Chemotaxis, Jimmie Marquette Smith

Loma Linda University Electronic Theses, Dissertations & Projects

This study localized 1) the site of ATP utilization in the signal transduction pathway of bacterial chemotaxis and 2) the point of convergence of the methylation-independent systems of chemotaxis with the methylation-dependent system. The site of ATP utilization was localized at the CheY protein/switch point. In an Eaeheriehia call strain (BT3077) containing the cheY, motor and switch genes, ATP depletion, accomplished by treating the cells with arsenate, suppressed the CheY protein-induced tumbling. ATP was not required by the switch for directing the clockwise and counterclockwise rotations of the flagellar motor. ATP did not appear to be required for normal steady-state …

Running Endurance In 27-Hour Fasted Humans, Kristin A. Carlson

Loma Linda University Electronic Theses, Dissertations & Projects

Nine male marathon runners were exercised to exhaustion to determine the effects of a 27-hour fast on endurance performance. Each subject completed two exercise tests at 72% peak oxygen uptake (Vo₂max), one following a 27-hour fast and one three hours after a pre-exercise meal, in random order. Fasting caused a 44.7±5.8% (±SE) decrease in endurance performance (p2(9.3±2.0%), heart rate (8.4±2.4%), rating of perceived exertion (RPE), and psychological fatigue, evident within the first 60 minutes of exercise. There was no difference in plasma glucose or epinephrine levels. Muscle glycogen degraded at the same rate (0.48±.15 vs 0.47±.28 u moles …

Selenium-Induced Enhancement Of Hematoporphyrin Derivative Phototoxicity In Murine Bladder Tumor Cells, Jeffrey M. Tosk

Loma Linda University Electronic Theses, Dissertations & Projects

The phototoxicity of hematoporphyrin derivative (Hpd) to murine bladder tumor (MBT-2) cells was studied in vitro. It was observed that selenium in the form of sodium selenite enhanced Hpd-sensitized photodamage in MBT-2 cells under conditions where the selenite alone was non-toxic. Sodium selenite was found to enhance the fluorescence emission of Hpd and augment the Hpd-sensitized photooxidation of tryptophan. The data indicate that sodium selenite is able to disaggregate Hpd, thereby enhancing Hpd-sensitized phototoxicity.

Fetal Whole-Body Fluid, Cardiovascular And Endocrine Dynamics : Computer Analysis Of Regulatory Mechanisms, Peter Stuart Gold

Loma Linda University Electronic Theses, Dissertations & Projects

The dynamics of transcapillary fluid and protein distribution and endocrine regulation of cardiovascular function were studied in chronically instrumented fetal sheep during the third trimester. Average experimental changes in vascular pressures, blood volume, plasma hormone concentrations, hematocrit and plasma protein concentration were analyzed using mathematical modeling and parameter optimization techniques in order to determine values for the major parameters which regulate fluid, protein and endocrine dynamics and to determine endocrine dose-response relationships to changes in cardiovascular function. The hormones which were considered are arginine vasopressin (AVP), angiotensin II (AII), epinephrine (EPI) and norepinephrine (NE). Vascular disturbances which were considered include …

The Parotid Salivary Glands. I. Potential Role Of A Parotid Factor Modulating Pancreatic Β-Cell Function. Ii. An Immunohistological Study To Identify Parotid Hormone Secreting Cell(S), Denise S. Cook

Loma Linda University Electronic Theses, Dissertations & Projects

The physiologic role of the parotid glands is more complex than its recognized salivary function. Various investigators have suggested an intriguing relationship between the parotids and the pancreas, both endocrine and exocrine in nature.

We studied in rats the contribution of salivary glands in the regulation of β-cell function in response to an acute intra-arterial glucose challenge in parotidectomized, submandibulariectomized and totally sialoadenectomized animals. Fifteen days post-parotidectomy or total sialoadenectomy, the β-cell response, at 2 minutes post-glucose infusion, diminishes and stabilizes at about 40% of the preoperative value. Concurrent with the depressed insulin secretion a correspondingly higher glucose titer was …

A Behavioral And Ecological Study Of The Fiddler Crab Uca Crenulata, Magali Hantson-Parker

Loma Linda University Electronic Theses, Dissertations & Projects

The social interaction and behavioral activities of a population of fiddler crabs, Uca crenulatat located in the "Aqua Hedianda" lagoon in Carlsbad, California, is the subject of this study.

Variations in environmental factors as well as seasonal behavioral changes cause an important fluctuation in the male to female ratio and in population density.

A daily and seasonal variation is observed in the different behavioral activities displayed by the crab colony and are caused by biotic and abiotic environmental factors and by intrinsic hormonal changes.

A male color variation from dark to light is related to behavioral changes during the breeding …

The Role Of The Salivary Glands In Uptake Of Fluoride In Teeth And Bone, Robin E. Vance

Loma Linda University Electronic Theses, Dissertations & Projects

The cariostatic capability of fluoride is generally recognized, in addition, it may also have a beneficial effect on bone. Fluoride is thought to exercise its cariostasis through a local effect on teeth, however, the possibility exists that fluoride exerts its action through a systemic mechanism. Fluoride uptake by rat teeth and its effectiveness as a cariostatic substance was studied in parotidectomized, submaxillariectomized, and totally sialoadenectomized animals (both parotid and submaxillary glands removed). The uptake of fluoride in bone was also quantitated for comparison purposes.

Rats were injected daily with 15 micromoles of fluoride dissolved in 0.1 ml saline. The rats …

Autoradiography Of Photomembrane In Hemigrapsus Nudus, Carol Fulenwider

Loma Linda University Electronic Theses, Dissertations & Projects

Protein synthesis was studied in the visual cells of Hemigrapsus nudus by light microscope autoradiography. Two hours before sunset, crabs were injected with a single dose of tritiated leucine and sacrificed at time intervals coincident with dynamic retinal changes observed in electron microscope (EM) studies of related Arthropods (Blest, 1978 and Stowe, 1980).

Two separate experiments were performed to examine time periods in the renewal process. Some periods in each experiment were overlapped to develop more accurate decay curves. Experiment I followed time regimes of 0.5, 1.5, 2.5, 3.0, 3.0, 5.0, and 6.0 hours after sunset. Autoradiographs of retinula cells …

The Role Of Vasopressin In The Fetal Renal Response To Hypertonicity, Lori L. Woods

Loma Linda University Electronic Theses, Dissertations & Projects

In order to study the effects of hyperosmolality on fetal renal function and to gain insight into the role of AVP in the fetal urine concentrating mechanism, two types of studies were performed. In whole animal studies 9% NaCl was injected intravenously into 8 chronically catheterized pregnant ewes of 130-135 days gestation and their fetuses, followed by a continuous infusion of 9% NaCl into the ewes. Fetal and maternal plasma osmolalities rose initially by 5% and remained elevated for the next four hours. Fetal arterial and venous pressures increased transiently. Fetal urine flow increased transiently by 73%, remained elevated for …

Extrathyroidal Human Biochemistry Of Monoiodotyrosine, Stanley Andrew Tan

Loma Linda University Electronic Theses, Dissertations & Projects

The existence of extrathyroidal monoiodotyrosine (MIT) has been debated because of uncertain results from measuring serum MIT. The reason is that the isotopic and chromatographic assays used have not been sensitive enough. This investigation undertook to establish the existence of MIT in serum utilizing a radioimmunoassay (RIA), to study the physiology of serum MIT, and to discover the pharmacologic effects of exogenous MIT.

MIT-binding antibody was raised in rabbits by immunization with an MIT-porcine thyroglobulin conjugate. The antiserum bound 40% of the labeled MIT at a final dilution of 1:1000. Incubation of 100 µ1 antiserum with 50 pg [^{125 …}

Age-Related Changes Of Neurites In Meissner Corpuscles Of Diabetic, Vicky R. Ras

Loma Linda University Electronic Theses, Dissertations & Projects

This thesis is based on a qualitative and quantitative study of the neural component of Meissner corpuscles of diabetic and non-diabetic mice. Age-related changes were also documented in these mechanoreceptors. Corpuscles from forty-six diabetic mice and forty-six non-diabetic mice ranging from 2.5 to 17 months old were studied. Forepaw index digital pads were formalin-fixed and frozen-sectioned parallel to each digit and perpendicular to the skin. Serial sections were then silver-impregnated to allow light microscopic examination of the neurites in the corpuscles.

Neurites became more coarse, tortuous, branched, varicose, and thus more complex until middle age. Corpuscle size appeared greatest at …

The Effect Of Feeding, Bilateral Parotidectomy, And Pilocarpine Treatment On Parotid Hormone Secretion In The Pig, Jocelyn Celestin

Loma Linda University Electronic Theses, Dissertations & Projects

The effect of feeding, bilateral parotidectomy, pilocarpine treatment, visual and olfactory, and masticatory stimuli on parotid hormone (PH) secretion is reported. Feeding a regular chow was shown to be a potent stimulus for PH secretion. The parotid endocrine system is highly sensitive to the eating stimulus, since a period of feeding lasting 30 sec is enough to cause a significant increase in PH secretion. The parotid glands are the principal source of PH as shown by the marked decrease in basal PH titer, and a virtual absence of response of PH to feeding in parotidectomized pigs. Pilocarpine administration provoked profuse …

Vascular Effects Of Physalia Physalis Venom, Jose S. Loredo

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to identify the effects of Physalia physalis (Portuguese Man-of-War) venom on vascular smooth muscle and elucidate its mode of action. We utilized the in vivo approach by functionally isolating the skeletal muscle vasculature of the dog's hind leg, and the in vitro approach by studying rabbit arterial ring segments.

Twelve male mongrel dogs were anesthetized with 35 mg/kg sodium pentobarbital. Arterial pressure was measured from the aortic arch and the cranial femoral artery, a cephalad branch of the femoral artery. The skeletal muscle venous blood flow of the hind leg was functionally isolated. Femoral …

Effects Of The Removal Of Adherent And Phagocytic Cells On The Spleen Cell Lymphoproliferative Response Of Tumor Bearing Mice, Aileen M. Hyde

Loma Linda University Electronic Theses, Dissertations & Projects

Cell-mediated immunity was investigated in two BALB/c mouse tumor systems using the lymphocyte transformation test with phytohemagglutinin as the mitogen. This lymphoproliferative response was quantitated using the Stimulation Index (SI). Spleen cells from mice injected with #51 cells, a chemically-transformed colon cell line, produced a SI value equal to that of normal mice. There was no evidence for suppressor cell activity in cell mixing experiments in which spleen cells from #51 cell-injected mice were mixed with spleen cells from normal mice. Following macrophage removal by Sephadex G-10 columns an d carbonyl iron ingestion, there were no significant changes in the …

Mast Cell Histamine Release Induced By Portuguese Man-Of-War (Physalia) Venom, A. Lester Flowers

Loma Linda University Electronic Theses, Dissertations & Projects

Richet and Portier studied the immunization of dogs against attenuated toxic extracts of the sea anemone and showed that, when given secondary injections of sublethal amounts of native toxic extracts, the dogs experienced severe pruritus and insensitivity followed by death. They called this increased sensitivity to the toxins, anaphylaxis. Richet and Portier, and later Jacques and Schachter, and Uvnäs also studied the direct pruritic and histamine releasing effects of cnidarian (e.g. Physalia, Actinia, Cyanea), toxic extracts. While the anaphylactic effect, discovered by Richet and Portier, has been extended by numerous studies to provide the foundation of our current knowledge of …

The Neural Organization Of The Lamina Ganglionaris In The Crab Hemigrapsus Nudus A Light And Electron Microscope Study, Hsu-Cheng Huang

Loma Linda University Electronic Theses, Dissertations & Projects

The gross structure and the neural arrangements in the optic lamina of crab Hemigrapsus nudus have been studied by light microscopy Golgi techniques and by electron microscopy. The lamina from distal to proximal is composed of a distinct cell layer, a fibular synaptic region, the plexiform layer, a spares cell layer, and the first optic chiasma. Golgi preparation of the lamina reveal four types of cells contributing to the lamina synaptic layer. Retinula cell axons and terminations, monopolar neurons with perikarya in the distal cell layer, tangential cells, neurons whose primary process enters from the chiasma with secondary processes branching …

The Role Of The Parotid Salivary Glands In The Regulation Of Insulin Secretion, Kenneth L. Millard

Loma Linda University Electronic Theses, Dissertations & Projects

Stress of handling, partial or complete sialoadenectomy, and the administration of parotid hormone (PH), sodium fluoride (NaF), or guanidino-succinic acid (GSA) were examined for effects on fasting plasma glucose and insulin or effects on intravenous glucose tolerance in male Sprague-Dawley rats. Basal glucose and insulin were substantially elevated as a result of the stress of translocation in large animals, but were not altered in small animals. A rise in plasma insulin occured in control animals 20 minutes following anesthesia and the removal of a blood sample by cardiac puncture but not in animals that had been handled twice daily for …

The Effect Of Exercise On Blood Flow In Pregnant Guinea Pigs, Marjorie Correll Sladek

Loma Linda University Electronic Theses, Dissertations & Projects

Recent investigations have shown decreased fetal weight in pregnant animals who were exercised regularly during pregnancy (Gilbert; Nelson; Longo, 1979; Terada, 1974). The purpose of this experimental study was to investigate fetal weight gain and measure blood flow in pregnant guinea pigs who were exercised 45 minutes per day; and thus answer the hypothesis that prolonged maternal exercise will cause decreased weight gain and decreased placental blood flow during pregnancy.

Twenty pregnant guinea pigs were exercised 15 minutes three times daily from 10 days gestation to approximately 60-62 days gestation (67 days being term) and were compared with 19 control …

Mechanisms Of Control Of Blood Flow In The Forelimb Of Sheep, Paul J. Marks

Loma Linda University Electronic Theses, Dissertations & Projects

Although much is known about the factors involved in the control of blood flow, the cellular mechanisms of their action are poorly understood. This study investigated the mechanisms of norepinephrine, epinephrine, isoproterenol, and acetylcholine.

First, in a constant pressure/variable flow preparation we characterized the sheep brachial artery blood flow response to, and recovery from, 10-min infusions of each of these drugs. Then we used a computer model to simulate changes in blood flow in response to altered ion permeabilities or pump speeds (the mechanisms). We tried to produce responses like those to the drug infusions so that we could infer …

A Light And Electron Microscopic Study Of Visual Neurons In The Medulla Externa Of The Crab Hemigrapsus Nudus, Yu Cheng Liao

Loma Linda University Electronic Theses, Dissertations & Projects

The decapod crustacean with a relatively well-defined visual system have contributed significantly to our understanding of visual neuron morphology and physiology. The general morphology of the optic lobes of several decapods were initially described by Parker (1897) and Hanstrom (1924). In the past few years, several light and electron microscope studies have been made on the lamina ganglionaris: the first optic ganglion, of the lobster (Hamori and Horridge, 1966a); the crayfish (Hafner, 1974; Nassel, 1976a), and the crab (Stowe et al., 1977; Rafuse et al., in preparation). As yet, no adequate description has been made of the visual neurons in …