Research Methods in Life Sciences Commons^™

Effects Of A Serine 364 To Proline Mutation Of The Connexin43 Protein In Transgenic Mice, Chia-Ling Nhan-Chang

Loma Linda University Electronic Theses, Dissertations & Projects

[Abstract Not Included]

Insulinlike Growth Factor 1- And 2-Augmented Collagen Gel Repair Of Facial Osseous Defects, James S. Toung, Roy C. Ogle, Raymond F. Morgan, William H. Lindsey

School of Medical Diagnostics & Translational Sciences Publications

BACKGROUND: Defects of the facial bone structure are common problems for the facial plastic surgeon. Native type 1 collagen gels (T1CGs) have been shown to mediate repair of facial critical-size defects in rat models.

OBJECTIVE: To evaluate the efficacy of T1CG augmented with insulinlike growth factor (IGF) 1, IGF-2, and a combination of IGF-1 and IGF-2 on the repair of facial critical-size defects in a rodent model.

METHODS: Twenty-four retired male breeder Sprague-Dawley rats were divided into 4 groups of 6 animals. Facial critical-size defects were created by removing the nasalis bones with a bone-cutting drill. Defects were treated with …

Localization Of Sodium, Potassium-Adenosine Triphosphatase In The Cerebral Cortex Of Developing Rats, Maki Ujiie

Loma Linda University Electronic Theses, Dissertations & Projects

Active transport via Na⁺, K⁺-ATPase plays an important role in establishing and maintaining proper ionic gradient across all mammalian cell membranes. A strict regulation of Na⁺, and K⁺ ion levels is especially important in excitable cells such as neurons and myocytes. Inhibition of the enzyme is associated with several pathological conditions and has serious detrimental effects on cerebral cortical cells. Yet the enzyme appears to be limited in amount and distribution in newborn rats. In this study, Na_⁺, K⁺- ATPase expression and distribution in early postnatal rats were studied …

A Model Using Radiation And Pws4-Htnf-Α Gene Therapy For Treatment Of Glioblastomas, Angelo G. Baher

Loma Linda University Electronic Theses, Dissertations & Projects

The efficacy of radiotherapy for cancer is limited by the dose that can be safely delivered to the tumor without causing debilitating side effects. In addition, successful treatment of highly malignant tumors such as glioblastomas is likely to require adjunctive therapies to enhance tumor response to radiation. Previous studies have shown immunomodulation and a synergestic reduction in tumor volume of malignant tumors when tumor necrosis factor-α (TNF-α) protein is administered prior to radiation. The major goal of the present investigation was to evaluate the efficacy of pWS4-human TNF-α (pWS4-hTNF-α), a new plasmid construct that expresses human TNF-α protein, together with …

Regeneration In Periodontal Defects With Rhbmp-2 : A Dosage Study, Paola Guglielmoni

Loma Linda University Electronic Theses, Dissertations & Projects

Bone morphogenetic proteins (BMPs) have been shown to induce bone formation in ectopic and orthotopic sites. This inductive capability has led to their evaluation as possible adjuncts in periodontal reconstructive therapy. Indeed, studies have reported periodontal regeneration following surgical implantation of recombinant human BMP-2. This study evaluated regeneration of alveolar bone and cementum following periodontal reconstructive surgery including implantation of a construct consisting of sterile lyophilized rhBMP-2 in buffer adsorbed onto an absorbable collagen sponge. Critical size mandibular supra-alveolar periodontal defects were surgically created, and an incomplete block design was used to evaluate the regenerative potential of rhBMP-2 at 0.05, …

A Cytochemical Evaluation Of Blood-Brain Barrier Sodium, Potassium- And Calcium-Adenosine Triphosphatase Polarity, Panya Steve Manoonkitiwongsa

Loma Linda University Electronic Theses, Dissertations & Projects

The blood-brain barrier (BBB) is formed by cerebral vascular endothelial cells. Brain ion and fluid homeotasis essential for proper neural functioning is due to the BBB. Sodium-potassium and calcium-activated adenosine triphosphatase (Na⁺, K⁺-ATPase and Ca²⁺-ATPase) serve as one of the main mechanisms controlling brain Na⁺, K⁺, and Ca²⁺ concentrations. The present accepted concept is that both of these enzymes are localized to the abluminal plasma membrane of endothelial cells although there have been contrary results from some studies. Because of these discrepancies, further work was needed. Various cytochemical procedures …

Study Of The Hiv-1 Gene Regulatory Proteins Tat And Rev By The Two-Hybrid System In Yeast, David Allen Elkins

Loma Linda University Electronic Theses, Dissertations & Projects

Tat and Rev, small proteins encoded by the Human Immunodeficiency Virus type 1 (HIV-1), regulate its pattern of gene expression within infected cells. Tat increases transcription from the integrated pro virus by approximately a thousand-fold; Rev effects a shift in the pattern of splicing of the viral mRNA. Both are likely to interact with cellular proteins in executing their respective functions. Tat has additional activities (including neurotoxicity and inhibition of lymphocyte activation) which may be extraneous to its viral functions.

In order to identify cellular proteins interacting with Tat and Rev, the genes for both were cloned into plasmid vectors …

Periodontal Repair In Dogs : Effect Of Recombinant Human Transforming Growth Factor Beta-1 On Guided Tissue Regeneration, Saghi Shayan Razi

Loma Linda University Electronic Theses, Dissertations & Projects

The objective of this study was to evaluate bone and cementum regeneration in the critical size, supraalveolar, periodontal defect model following surgical implantation of recombinant human transforming growth factor beta-1 (rhTGFß-1) in conjunction with guided tissue regeneration (GTR). Five male beagle dogs were used in a split-mouth design. Alternate jaw quadrants in consecutive animals received GTR with rhTGFß-1 in a resorbable calcium carbonate carrier. Contralateral jaw quadrants received GTR with carrier only (control). The healing interval was 4 weeks. Clinical healing was generally uneventful, however, minor membrane exposures were observed for both treatments with limited gingival inflammation. All defects with …

Bone Morphogenetic Proteins And Periodontal Repair, Michael B. Lee

Loma Linda University Electronic Theses, Dissertations & Projects

For over thirty years now, research has been carried out to isolate and purify bone morphogenetic protein (BMP), a substance which has been shown to induce heterotopic bone formation in various animal species. Recent advances in the fields of developmental biology, molecular biology and genetics, have shown that the BMPs not only are responsible for postfetal bone induction (including normal bone remodeling, healing and repair), but are also critical during embryogenesis - not only in regards to the skeletal system, but quite possibly in the morphogenesis and pattern formation of other tissues and organs as well.

Due to their bone …

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 …

The Production And Characterization Of A Monoclonal Antibody To A Naturally Occurring Aminomalonic Acid Epitope And A Comparison With An Antibody To A Synthetically Derived Aminomalonic Acid Epitope, James L. Gulley

Loma Linda University Electronic Theses, Dissertations & Projects

The goal for this project is to undertake the first step in the study of blocking metastasis by a monoclonal antibody. The long range goal of this line of research is to study a novel mechanism for the blocking of tumor metastasis in general and prostatic cancer metastasis in particular. The problem that this addresses is the growing number of cases of prostatic cancer in the increasingly aging male population. This cancer is not lethal unless it metastasizes, yet there is no cure for the metastatic disease. The inherent specificity of a monoclonal antibody combined with the uniqueness of the …

Cerebral Microcirculatory Effects Of Maturation, Scott R. Elliott

Loma Linda University Electronic Theses, Dissertations & Projects

The present studies demonstrate that in the second (2B) and fourth (4B) branches of newborn and adult sheep middle cerebral arteries, 5-HT2 serotonergic receptors mediate contractile responses to serotonin and that alpha-1 adrenergic receptors mediate contractile responses to norepinephrine. In addition, tissue sensitivity to 5-HT and NE decreases significantly with maturation, but does not vary with branch order. These age-related changes were associated with a decrease in affinity and maximum response in 2B and 4B segments of 5-HT and NE contracted arteries, respectively. Norepinephrine and 5-HT occupancy at the pD₂ rose significantly in 2B segments, but did not change …

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 …

Catecholamines And The Regulation Of Uterine Contractions In The Pregnant Rhesus Macaque, Cahleen Mae Mcnutt

Loma Linda University Electronic Theses, Dissertations & Projects

This study was designed to test the hypothesis that: 1) maternal and/or amniotic fluid catecholamines or prostaglandins display nocturnal activity rhythms similar to those of the myometrial contractility in the pregnant rhesus macaque and, 2) catecholamines stimulate prostaglandin production by fetal membranes. Paired maternal arterial blood and amniotic fluid samples were collected at 0900 h (AM) and 2100 h (PM) from chronically catheterized rhesus macaques until delivery and analyzed for prostaglandin metabolites (PGFM and PGEM-II) and catecholamines (norepinephrine, epinephrine, and dopamine). Uterine activity data was continuously recorded. A rhythm in uterine contractility was observed, with peak activity between 1900 and …

Effect Of Glucose Administration On Hamster Liver S9-Mediated Mutagenesis, Metabolism And Dna-Binding Of Benzo[A]Pyrene And Aflatoxin B1, Daniel C. Rubano

Loma Linda University Electronic Theses, Dissertations & Projects

Hamster liver S9 prepared from control animals and animals given 30% glucose in drinking water 48 h before time of sacrifice was used in studies of benzo[a]pyrene (BaP) and aflatoxin (AFB₁)-induced mutagenesis, metabolism of BaP and AFB₁, and metabolite binding to calf thymus DNA. BaP-induced mutagenesis in Salmonella typhimurium TA100 was reduced 38.5% while AFB₁-induced mutagenesis was increased 36% by S9 from glucose-treated hamsters. The reduction of [³H]BaP metabolite binding to calf thymus DNA in incubations with S9 from glucose-treated hamsters correlated with a decrease in unknown BaP metabolite-deoxyribonucleoside adducts isolated by …

Effect Of Photoperiod On Developmental Morphology And Enolase Isoenzyme Immunohistochemistry In Rat And Djungarian Hamster Superficial Pineal Glands, Chalmer D. Mcclure

Loma Linda University Electronic Theses, Dissertations & Projects

The best understood functional activity of the pineal gland is its diurnal production of melatonin in response to environmental lighting cues. Several enzymes of the melatonin pathway respond to daily photoperiod changes, for example hydroxyindole-O-methyltransferase (HIOMT) and serotonin N-acetyltransferase (SNAT). Increased levels of the glycolytic enzyme neuron-specific enolase (NSE) are thought to reflect increased physiological demands placed on neurons and neuroendocrine tissues. Homodimer non-neuronal enolase isoenzyme (NNE) is immunolocalized to cells, and the hybrid enolase (consisting of subunits from NSE and NNE) has been seen in cerebellar stellate and basket cells. Although not rate limiting, concentrations of both NSE and …

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 …

Isolation And Partial Characterization Of Basic, Sperm-Specific, Nuclear Proteins In The Dog And Hampster, Richard William Hall

Biological Sciences Theses & Dissertations

The purpose was to determine whether dogs and hamsters contain the same sperm-specific protamine and testis specific proteins (TP) as other eutherian mammals previously studied. The proteins (protamine and TPs) were isolated from spermatids and mature spermatozoa, and were subjected to electrophoresis in an acid-urea, polyacrylamide gel system according to the procedure of Panyim and Chalkley (1962). The results indicated that, regardless of the anatomical location of sperm acquisition, acid precipitation technique, or denaturing agents used, epididymal and testicular samples from both the dog and hamster contained protamine in elongated spermatids and mature spermatozoa. The protamines from dogs and hamsters …

Decreased Triiodothyronine Binding To The Hepatic Nuclear Thyroid Hormone Receptor In The Diabetic Mouse, Thomas J. Dewind

Loma Linda University Electronic Theses, Dissertations & Projects

The diabetic C57BL/KsJ-db m mouse has abnormal thyroid hormone levels and indications of thyroid hormone resistance. To investigate the basis of these abnormalities, the hepatic nuclear thyroid hormone receptor was extracted with 0.4 M KCl, 1.1 mM MgCl₂, 20 mM Tris/HCl, pH 7.9 from hepatocyte nuclei of normal C57BL/KsJ, heterozygous C57BL/KsJ-db m (db/m), and diabetic C57BL/KsJ-db m (db/db) mice. Normal and heterozygous mice were grouped together as the controls. Triiodothyronine (T₃) binding studies at 4°C using nitrocellulose filtration to separate free T₃ from receptor bound T₃ demonstrated an …

Policy For Identifying And Assessing The Health Risks Of Toxic Substances, Maine Bureau Of Health

Maine Collection

Policy for Identifying and Assessing the Health Risks of Toxic Substances

by Norman T. Anderson, Environmental Toxicology Program, Division of Disease Control, Bureau of Health (February, 1988).

Contents: Section I: Introduction / Section II: Methods / Section III: Exposure Assessment / Section IV: Hazard Identification / Section V: Hazard Assessment / Section VI: Risk Characterization / List of Figures / List of Tables

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 Effect Of Dietary Fat Level On Tumor Development And Immunity In Balb/C Mice Fed Casein Of Wheat Gluten As Protein And Challenged With Herpes Type 2-Transformed Cells, Helen Drakou

Loma Linda University Electronic Theses, Dissertations & Projects

A high percentage of fat in the diet has been implicated through epidemiological studies in several human cancers. Studies in experimental animals have produced evidence that increasing the fat in the diet decreases the animal’s ability to restrict tumor development and growth. In previous work done in this laboratory with BALB/c mice injected with herpes simplex Type 2-transformed mouse cells (H238), the effects of a diet which greatly enhanced tumor growth was compared with one which restricted tumor growth. The latter, a low (5%) fat, low protein diet, in which the protein was casein, was also found to produce a …

Sprague-Dawley Rats Fed Milk Or Beef Protein : Differences In Response To 1,2-Dimethylhydrazine Carcinogenesis, Stanley W. L. Ng

Loma Linda University Electronic Theses, Dissertations & Projects

Colon cancer is responsible for a high percentage of cancer deaths in developing countries, and there is convincing epidemiological evidence that meat protein and fat in the diet increase the incidence of this form of cancer. An animal tumor model which has been used by many investigators interested in colon cancer is the 1,2-dimethylhydrazine (DMH)-rat or DMH-mouse tumor model. In previous work done in this laboratory the DMH-BALB/c mouse tumor model was used to compare the production of colon tumors in mice fed a diet using non-fat powdered milk as a source of protein with those in mice fed beef …

Interaction Of Putative Estrogens And The Estrogen Receptor System In Leydig Cells In The Balb/C Mouse Testis Resulting In The Initiation Of Dna Synthesis, R. Lloyd Juriansz

Loma Linda University Electronic Theses, Dissertations & Projects

Continuous administration of estrogens for 7-9 months, both steroidal and nonsteroidal, to male BALB/c mice, leads to the formation of testicular Leydig cell tumors. Three days following the subcutaneous implantation of a pellet of estrogen in cholesterol, there is a peak in the incorporation of ³H-tymidine into the DNA of the interstitial cells. These effects are hypothesized to be mediated by the estrogen receptor system in the Leydig cell. Common experimental techniques for the measurement of hormone binding, such as dextran coated charcoal treatment, proved to be impossible to employ in this system, therefore a procedure was developed using …

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 …

The Effect Of Hypercholesterolemia On The Membrane Lipids, 3-0-[¹⁴C] Methylglucose Transport, And 2,3-Diphosphoglycerate Levels In Rat Erythrocytes, Edwin J. Lester Jr.

Loma Linda University Electronic Theses, Dissertations & Projects

An increase in dietary cholesterol and cholic acid will produce hypercholesterolemia in rats. For ten months, two groups of rats (six in each group) were fed commercial rat pellets (control group) or rat pellets plus cholesterol (1%) and cholic acid (0.25%) (experimental group). A blood sample from each animal was divided into three aliquots for three separate experiments on the erythrocytes: a membrane cholesterol and phospholipid determination, a 3-0-[¹⁴C] methylglucose (30MG) transport determination, and a 2,3-diphosphoglycerate (2,3 DPG) determination. The 30MG transport and 2,3 DPG aliquots were each incubated in the same five concentrations of 30MG and glucose …

Isolation And Chemico-Physiologic Characterization Of A Parotid Hormone Activity From Porcine Glands, Jean-Marc Tieche

Loma Linda University Electronic Theses, Dissertations & Projects

For the past decade, evidence has accumulated which suggests that the resistance of the teeth to dental decay is in part under systemic control. It was shown that the resistance is accomplished through the optimal operation of a dentinal fluid transport mechanism which is believed to be hormonally controlled by the hypothalamic-parotid gland endocrine axis. Although circumstantial evidence for such an endocrine function was strong, the isolation of a parotid hormone which stimulates the dentinal fluid transport mechanism remained to be accomplished.

Using modern biochemical techniques, a methodology was designed to isolate and purify the hormone from porcine parotid glands. …

Human Placental Alkaline Phosphatase And Steroid Metabolism By Rat Adrenals, Allen G. Meier

Loma Linda University Electronic Theses, Dissertations & Projects

Human placental alkaline phosphatase was purified by butanol extraction, methanol precipitation and chromatography on DEAE-cellulose. The pH optimum was found to be 10.9. The enzyme was competitively inhibited by di-ethyl-p-nitrobenzyl-phosphonate and copper sulfate. An increase in enzymatic activity occurred in the presence of the phosphate ion (HPO₄) and ATP.

The enzyme was crystallized from a 40% saturated solution of ammonium sulfate and shown to be homogeneous by sedimentation analysis. Homogeneity of the enzyme was also demonstrated using poly-acrylamide-gel-electrophoresis. At a pH of 7.5% the electrophoretic pattern yielded a single band and showed no significant contamination.

The metabolic transformation …

Effects Of Cariogenic And Noncariogenic Diets On The Concentration Of The Parotid Hormone Releasing Factor In Rat Hypothalami, Melva Joan Brown

Loma Linda University Electronic Theses, Dissertations & Projects

Hypothalamic and cortical extracts from various cariogenically grouped rats which had been maintained on either a Purina diet or a high sucrose diet (HSD) for three months were infused intravenously into 28 days old rats to determine if there was a titer of parotid hormone releasing factor (PRF) capable of facilitating fluid movement (FM) in the teeth. The hypothalamic and cortical extracts obtained from Purina-fed rats with 0-caries and the hypothalamic extracts from BSD-fed rats conclusively demonstrated FM stimulatory ability. Other Purina-fed groups were essentially biologically ineffective, however, extracts from HSD-fed caries groups including scores 11-40 demonstrated extremely potent FM …

The Effect Of Insulin, Fluoride And Methyl Xanthines On The Hypothalamic-Parotid Gland Endocrine Axis, Reagan Ondler

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine the effect of insulin and fluoride on dentinal fluid movement (FM) in high-sucrose fed rats as mediated through the hypothalamic-parotid gland endocrine axis. In conjunction with the fluoride study, the possible involvement of cAMP was examined through the use of several methyl xanthines which are recognized as phosphodiesterase inhibitors.

Twenty-one day old, male Sprague Dawley rats were maintained on a high-sugar diet (62% sucrose) for 8-9 days at which time intravenous or arterial infusions of insulin, fluoride or the methyl xanthines were performed. Additional procedures included collecting plasma from rats which had …