Research Methods in Life Sciences Commons^™

The Effect Of Systemic Doxycycline On Alveolar Bone Loss Following Periradicular Surgery, G. Reed Cummings

Loma Linda University Electronic Theses, Dissertations & Projects

Studies have shown an average of 0.5 mm to over 1.0 mm of bone loss following full thickness flap reflection. Recent investigations have revealed that the tetracycline family of antibiotics can prevent bone loss. The purpose of this study was to determine the effect of systemic Doxycycline on crestal alveolar bone loss following periradicular surgery in Beagle dogs.

The experiment was divided into two phases. The first phase served as the control (Non-Doxycycline), the second phase as the experiment (Doxycycline). Full thickness flaps were reflected in the mandibular left or right quadrant (control side) of five Beagle dogs. Using a …

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 …

The Creation Of Transgenic Animal “Models” For Human Genetic Disease, Bernard Rollin

Biomedicine and Animal Models in Research Collection

Transgenic animals will be created to study human genetic disease as soon as the technological capability exists to do so. Extant laws permit such animals to be created. The mindset of the research community makes it inevitable. It is also clear that such diseases can cause enormous amounts of pain and suffering. Responsible researchers need to explore all possible avenues for controlling such pain and suffering. Thus far the research community has not engaged this issue vis a vis animals. The development of methodologies for controlling pain and suffering is likely to be exportable to numerous areas of animal research, …

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 …

Proto-Oncogene Regulation By Growth Factors In Bone Cells, Harold Lyndon Merriman

Loma Linda University Electronic Theses, Dissertations & Projects

Previous studies have shown that bone cells in culture produce a number of growth factors that are important in bone regulation. Chick and mouse primary calvarial cultures consist of a mixture of cell types that make it difficult to interpret the results from these model systems. In contrast, MC3T3-E1 cells are a clonal mouse osteoblast-like cell line. Since MC3T3-E1 cells consist of a single population of calvarial cells, they make an ideal system in which to study the autocrine effects of bone growth factors.

Based on this work, MC3T3-E1 cells are now known to produce IGF-I, TGF-beta and IGF-II in …

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 …

In Vitro Evaluation Of Cancer Patient Immune Responses Following Infusion Of Radiolabeled Murine Monoclonal Antibody, Kelly A. King

Loma Linda University Electronic Theses, Dissertations & Projects

Several monoclonal antibody (MAb) types derived from mice have been developed specifically for the use of targeting human tumors. The specificity of these murine MAb’s for their respective tumor antigens is very high making them potentially good immunotherapeutic agents for cancer treatment and diagnosis. A limiting factor in using these murine MAb’s in patients is the development of human anti-mouse antibody (HAMA). The presence of HAMA may reduce the effectiveness of MAb for tumor targeting. If patient sensitization could be quickly detected following the initial infusion of MAb, then future infusion could be altered or terminated to prevent further sensitization. …

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 …

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

Hyperosmotic Modification Of Brain Extracellular Space And Blood-Brain Barrier In The Rat As Observed By Electron Microscopy, Susan A. Meacham

Loma Linda University Electronic Theses, Dissertations & Projects

The highly selective permeability of cerebral blood vessels, termed the blood-brain barrier, is due to endothelial tight junctions (zonulae occludentes). Hyperosmotic solutions reversibly open the blood-brain barrier. The purpose of this study is to determine the immediate effect of hyperosmotic arabinose perfusion upon the cerebrovascular endothelium, the morphology of the cerebral cortex, and the cortical extracellular space.

Twelve adult male Sprague-Dawley rats were separated into three groups of four animals each: control, intermediate, and extreme. Controls were perfused with a Tyrode's solution prewash followed by trialdehyde fixative. The intermediate group received a prewash of 740 mmol/kg arabinose followed by the …

A Semiquantitative Analysis Of The Chorda Tympani Taste Pathway In The Rat Brain With The 2-Deoxyglucose Method, Charles L. Hardison

Loma Linda University Electronic Theses, Dissertations & Projects

This thesis is based on a semiquantitative analysis of four nuclear relay centers [nucleus tractus solitarius (NTS), parabrachial nucleus (PBN), ventroposteromedial nucleus (VPM), gustatory neocortex (GNC)] in the chorda tympani nerve pathway. Metabolic changes were examined by the 2-deoxyglucose method in which one chorda tympani nerve was chemically stimulated and its contralateral side lesioned. Coronal sections of four taste centers were prepared for autoradiography and Nissl staining. Densities of the autoradiograms were determined by means of a video based image processor. Relative differences in the optical density ratios of the stimulated versus lesioned nuclear grey matter areas to white matter …

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 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 Effects Of 712-Dimethylbenz (A) Anthracene On Ovarian Steroidogenesis And Uterine Growth In The Mouse, Jeffrey Lynn Clark

Biological Sciences Theses & Dissertations

It has been previously demonstrated that 7,12-dimethylbenz(a) anthracene (DMBA) is an initiator of ovarian granulosa cell tumors. It is also known that DMBA leads to destruction of primordial oocytes, and that tumor induction may involve the interaction of pituitary gonadotropins. However, the effects of DMBA on ovarian steroidogenesis and uterine growth in relation to the tumorigenic process have not been investigated. Therefore, the present study was conducted to examine these parameters using adult C57Bl/6N mice treated in proestrus and diestrus II with 0.1 ml corn oil with or without 1.5 mg DMBA and killed 44 hours later. The uteri and …

The Rate Of The Healing Process In Venous Thrombi Produced By A Sclerosing Agent With Special Attention To Endothelial Lining, Kiyoshi Tanaka

Loma Linda University Electronic Theses, Dissertations & Projects

Despite extensive clinical and experimental investigations of venous thrombosis, relatively little is known about the early phases of healing of the venous thrombus. Soon after its discovery heparin has become the most popular agent for the prevention and treatment of venous thrombosis, but there are a number of unanswered questions regarding the most satisfactory treatment for venous thrombosis.

One area of controversy has been the duration of anticoagulation therapy for acute venous thrombosis. If the anticoagulant is discontinued too soon, the thrombus may continue to propagate. Prolonged anticoagulant therapy exposes the patient to the risk of serious hemorrhage. The objective …

Cell Mediated Immunity By Cytotoxicity Assay And The Effect Of Corynebacterium Parvum And Radiation On Mice Bearing Herpes-Induced Tumors, Robert B. Stagg

Loma Linda University Electronic Theses, Dissertations & Projects

Cell mediated immune (CMI) cytotoxic reactivity of Balb/c mice against H238 cells, a Herpes simplex virus (HSV) Type 2 - induced sarcoma, was measured by the ¹²⁵IUdR release assay. The Balb/c mouse response to the growing HSV-induced tumor, treated with radiation and , was measured by survival rate, tumor growth and immune cytotoxicity of spleen and peritoneal exudate cells (PEC) as determined by ¹²⁵IUdR release assay. Subcutaneous (s.c.) inoculation of 1 x 10⁶ H238 cells (high dose) produced progressive tumor growth while s.c. inoculation of 1 x 10⁴ H238 cells (low dose) produced no tumors. A …

The Relationship Of Alcohol Consumption In Rats To Morphine And Codeine Intake And The Metabolism Of Dopamine, Hsiu Fen Liu

Loma Linda University Electronic Theses, Dissertations & Projects

The effects of morphine and codeine free-choice alcohol consumption in male Sprague-Dawley rats were studied. Intakes of a 10% alcohol solution in milliliters per 100 gm. of body weight were on recorded weekly. No difference was found in the alcohol intake of rats given either a morphine-supplemented diet (0.01% of the diet) or daily injection of morphine sulfate (2 mg./kg.); however, there was a significant lower intake of water (p < .05) in those rats fed the diet with morphine. Total fluid consumption of both groups given the morphine-supplemented diet and daily injection of morphine sulfate was decreased (p < .05). It was found that morphine did not affect the percentage of total fluid consumed as alcohol or the weight gain.

Two levels of codeine phosphate (10 mg./kg. and 20 mg./kg.) were injected subcutaneously into rats twice a day. It was observed that the codeine significantly decreased alcohol intake in rats …

Cardioregulatory Role Of The Abdominal Ganglion Of Aplysia Californica, George Maeda

Loma Linda University Electronic Theses, Dissertations & Projects

An isolated heart-abdominal ganglion preparation of this mollusc was developed and used to study the cardioregulatory function of the ganglion and nerves. The heart was perfused with artificial sea water through an atrial cannula and the gastro-esophageal artery was catheterized for blood pressure monitoring. The presence and cardioregulatory effects of axons in the nerves was investigated by electrical stimulation. Fine-tipped glass microelectrodes inserted into ganglionic neurons were used to determine the relationship between the neuronal and cardiac activities.

The principal results are listed below.

1. Primarily inhibitory responses are obtained from both right and left connective stimulation, with some evidence for …

A Study To Demonstrate The Immediate Destination Of An Embolus Formed In The Lumen Of A Peripheral Venous Catheter, Rosemarie Morikone Emori

Loma Linda University Electronic Theses, Dissertations & Projects

This study was designed to show the immediate destination of an embolus formed in the lumen of an intravenous catheter placed in a peripheral vessel. The hypothesis stated that clots injected into a peripheral vessel will lodge in the lungs. A subhypothesis was that the clot may lodge anywhere along the circulatory pathway.

Indications of need for the study as shown by the review of literature were the following: (1) the complications resulting from the frequent use of intravenous polyethylene catheters, (2) experimental studies that showed that clots were formed around intravenous catheters, (3) the evidence that intravenous catheters predispose …

The Effect Of Varying Protein Intake On Trichinella Spiralis Infection In Mice, Clare K. Kwan

Loma Linda University Electronic Theses, Dissertations & Projects

Three hundred Swiss Webster albino mice three weeks of age were placed on low (8%), medium (24%), high (48%) protein levels and a commercial laboratory animal feed, Purina Chow for various lengths of time: (1) simultaneously with infection, and four weeks thereafter, (2) three weeks before infection and throughout the four-week infection period, and (3) six weeks prior to infection and during the infection period. The protein source was casein. Sixty of the 300 mice used served as noninfected controls, and the other 240 were each infected with 400 washed, suspended Trichinella spiralis larvae obtained from a rat by the …

A Study Of Regeneration Of Peripheral Nerve In The Rat, James C. Jay

Loma Linda University Electronic Theses, Dissertations & Projects

Due to improvements in fixation and embedding techniques a restudy of regenerating peripheral nerve was thought advisable in order to better understand and describe the processes which take place.

Femoral nerves of white Wistar rats were used. The lesions were made by either crushing or severing the nerve. After a period of regeneration, varying from 12 hours to six days, the wound was reopened and the injured portion fixed in situ with 1% osmium tetroxide. The tissues were then removed, dehydrated, embedded and sectioned. The sections were stained and studied with a modified RCA EMU2A electron microscope.

Observations revealed that …