Research Methods in Life Sciences Commons^™

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 …

Weaning Kimberley Cattle Pays Off, D Pratchett, Stuart Young

Journal of the Department of Agriculture, Western Australia, Series 4

Research results show that weaning Kimberley calves when they reach 140kg liveweight is one way of increasing herd productivity by changing management practices. However, removing the bulls from the breeding herd, rather than running them with the cows ywear round as is the practice, does not increase branding percentage.

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 …

The Inhibition Of Bone Formation Occurring Under Weightlessness : The Effect Of Skeletal Unloading On Serum Levels Of A Bone-Derived Growth Factor, Jean D. Sibonga

Loma Linda University Electronic Theses, Dissertations & Projects

A deleterious effect of spaceflight on human health is the loss of bone associated with the prolonged lack of gravitational stress on the skeleton. A potential for bone loss is indicated by the hypercalciuria and decreased heel bone density determined in Skylab astronauts. Histological studies of juvenile laboratory rats in actual spaceflight and in simulation models document a suppression of bone formation with little alteration of bone resorption. The mechanism for net bone loss needs to be defined in order to develop measures for its prevention or correction.

Skeletal growth factors, which may mediate coupling and locally regulate bone volume …

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 [6-14c] Glucose Autoradiographic Study Of The Rat Brainstem Under Hypercapnic And Hypocapnic Conditions: Identification Of Respiratory-Related Regions, Tobey M. Leung

Loma Linda University Electronic Theses, Dissertations & Projects

The effects of systemic hypercapnia on brainstem metabolism were studied with the [6-¹⁴C] glucose autoradiography method. Neuronal pools which are metabolically active take up more [6-¹⁴C] glucose and maybe revealed pictorially as darker areas on autoradiograms. Since a high concentration of carbon dioxide stimulates central chemoreceptors and hence enhances respiratory drive, the darker regions on the autoradiograms may represent regions concentrated with respiratory-related neurons. Two discrete regions in the ventrolateral medulla (a column near nucleus ambiguus and a column in the lateral reticular nucleus) appeared dark and were analyzed with an image processing system, which converted …

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 …

Effects Of Corticosteroids And Of Cyclosporin A On Trypanosoma Musculi In Mice And In Culture, Philip Stephen Schuyler

Loma Linda University Electronic Theses, Dissertations & Projects

The in vivo and in vitro effects of cyclosporin A and corticosteroids on Trypanosoma musculi were examined. Mice that received continuous administration of 6 mg/liter/day of dexamethasone in drinking water and 200 mg/kg hydrocortisone acetate as a single dose 24 hrs prior to injection with T. musculi had significantly higher and longer parasitemias, than controls. Body and spleen weights and B cell responsiveness were lower in test animals and there were some deaths. Mice injected with T. musculi that received 100 mg/kg/day cyclosporin A had longer, but not higher, parasitemias than controls. Corticosteroids appear to partially inactive antibody production (i.e. …

Electromagnetic Field Variations In The Activation Of Bone Cell Synthesis, Gary Ketcherside

Loma Linda University Electronic Theses, Dissertations & Projects

[Abstract Not Included]

Inventing The Skin You Love To Test, Rick Weiss

Popular Press Items

No abstract provided.

A New Invasiveness Scale: Its Role In Reducing Animal Distress, Kenneth J. Shapiro, Peter B. Field

Experimentation Collection

No abstract provided.

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 Non-Human Primate Model For Studying Corticotomy-Facilitated Orthodontic Tooth Movement, R. David Rynearson

Loma Linda University Electronic Theses, Dissertations & Projects

This study was undertaken to test the hypothesis that a corticotomised tooth moves as a tooth-bone unit when under orthodontic force. A non-human primate model was designed to test the hypothesis. The non-human primate selected was Macaca fasicularis. Three adult males with erupted third molars were chosen so that extrapolation could be made to the adult human. The methods employed included the following: 1) Each animal had one treatment quadrant and one control quadrant per arch; 2) Pre-op and post-op study models were made; 3) All 2nd premolars, 2nd molars, and 3rd molars were banded; 4) A full-thickness flap …

Histologic Host Response To Polyoxymethylene Prosthesis As A Temporomandibular Joint Condylar Replacement, Frederick R. Mathews

Loma Linda University Electronic Theses, Dissertations & Projects

Polyoxyinethylene (Delrin) is a polyacetyl homopolymer which has been used successfully in many orthopedic joint replacements. To determine histologic host response to Delrin as a temporomandibular joint condylar replacement condyles were removed from ten fully mature macaca fasicularis monkeys. The condyles were replaced with a total prosthetic Delrin condyle attached to a titanium mesh. Specimens obtained at one, two, and six months indicated total acceptance of the Delrin, remodeling of the glenoid fossa and formation of bone between the middle cranial fossa and the roof of the glenoid fossa. These findings would indicate Delrin is a viable option for condylar …

Meeting Offers Hope For Fewer Animal Tests, Iver Peterson

News Reports

No abstract provided.

Industry Toxicologists Keen On Reducing Animal Use, Constance Holden

Profiles

No abstract provided.

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 Case For The Use Of Animals In Biomedical Research, Carl Cohen

Morality and Ethics of Animal Experimentation Collection

No abstract provided.

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 …

Alternatives Sought To Save Lab Animals, Jim Detjen

Popular Press Items

No abstract provided.

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 …

The Use Of Dura Mater As A Meniscus Replacement In Tmj Surgery, Kim J. Dipasquale

Loma Linda University Electronic Theses, Dissertations & Projects

Internal derangement of the temporomandibular joint is recognized as a problem of significant magnitude in both medical and dental circles. The last decade has seen a steady progression in the knowledge and sophistication of not only the anatomy and physiology of the temporomandibular joint, but also in the techniques of non-surgical and surgical management of internal derangements. Surgical correction of the unrepairable disc has typically been addressed by performing a menisectomy followed by placement of a non-physiologic implant material.

The animal study reported here was performed in order to evaluate the histologic fate and biological compatibility of freeze-dried dura when …

Effects Of Lateral Mandibular Expansion On Mandibular Morphology In The Growing Rat : A Comparative Study Of Treatment Effects With Orthopaedic And/Or Surgical Procedures, Eric Looi

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to investigate the effects of mandibular expansion by orthopaedic and surgical procedures in the growing rat mandible.

Sixty-four 35 day old Sprague Dawley Harlan rats were divided into four groups of 16 rats each and categorized as the control, orthopaedic expansion, surgery without graft and surgery with graft respectively. Prefabricated appliances were used for orthopaedic expansion of the mandibles and maintaining surgical expansion at the symphysis in the respective groups. Oxytetracycline were given intraperitoneally to mark areas of bone remodeling. Half the number of rats from each group were sacrificed at the end of …

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 Case Against The Use Of Animals In Science, Donald J. Barnes

Experimentation Collection

As a scientist long committed to the understanding, prediction, and control of biological, physiological, and behavioral events, I have no objection to the animal as a legitimate focus of science. As a parent, a son, a sibling, and the proud recipient of unconditional positive regard from a few special people, I am vitally interested in matters of health and in the most ethically efficient use of available resources. As a member of a species which has evolved sufficiently to allow the relatively broad perspective of a "web of life" and at least a rudimentary concept of altruism, I have laboriously …

The Case For The Use Of Animals In Science, James A. Will

Experimentation Collection

Animals are now used extensively in research and teaching, and the appropriateness of their use appears to be questioned. Some people believe that we are in a new era where the animal activists have become much more influential, and that the antagonism between the scientists and these groups is worse than it ever has been. This does not appear to be the case. The preeminence of various influences seems rather cyclic, even perhaps influenced by such things as economic conditions or wars. At present, the question is often asked, "Should we continue to use animals in science?" The real question …

The Case For The Use Of Animals In Medicine, Gary F. Merrill

Experimentation Collection

The use of animals in medical research and teaching, and the public concern this has generated is not a new issue (Visscher 1969). Ever since scientists began using animals to investigate the function of the body in health and disease, there have been those who opposed their work (Fishman and Richards 1982). Whether this controversy is cyclic is not known, but most concerned biomedical investigators agree that the opposition is here to stay. The author shares this opinion, and thus maintains that it is in the best interest of all parties to be properly educated on the issues. Only through …

Ethics, Welfare, And Laboratory Animal Management, David J. Allan, Judith K. Blackshaw

Experimentation Collection

Animals have been used in medical research from as far back as 129-199 A.D. when Galen, a Greek medical scientist, used a pig for his experiments. In the sixteenth and seventeenth centuries, anatomical dissections were carried out on animals; Galvani used frogs in 1791 for his experiments and the Russian physiologist, Pavlov, carried out his famous dog experiments in the early 1900s. Since this time, large numbers of animals have been used in biomedical and other research. In 1963 the first edition of "The Guide for the Care and Use of Laboratory Animals" was published, and the United States Public …

Socialized Vs. Unsocialized Wolves (Canis Lupus) In Experimental Research, Harry Frank, Linda M. Hasselbach, Dawn M. Littleton

Experimentation Collection

In the experimental setting human contact is both more frequent and more intimate than in observational research, and the issue therefore assumes even greater importance. The present paper discusses two experimental studies of wolf information processing, one of which was conducted with unsocialized animals and one of which was conducted with socialized animals, and examines the both the management and methodological consequences of these approaches.